parity · color-opacity

opacity — 100.00% verified visual parity PASS 3 · FAIL 0 · REFERENCE-DISPUTED 1all categories ↑

REFERENCE-DISPUTED 3804 px · above-floor 1.09% · raw 1.14% max-page diff opacity-text-glyph-group · text-group · REFERENCE DISPUTEDAntialiasCoverageΔE 17.9

Chrome ref

ironpress

full-page >1.0%/channel diff

why: above-floor complete-page mismatch 1.090827% exceeds 1.0% PASS ceiling; visually accepted coverage phase; raw antialiasing coverage residue on a shared outline

Overlapping glyphs in one opacity:.5 element flatten before compositing; catches per-glyph alpha drawing where overlaps become too bright.

reference dispute: Both PDFs are rasterized by the same pinned pdftoppm command. Ironpress composites the overlapping glyphs as one opacity group: its fully painted glyph colour is the same #808080 as Chrome's (52,577 versus 52,595 pixels), so the overlap is not brightened by per-glyph alpha. The remaining raw diff is a one-device-pixel contour residue. The Ironpress PDF embeds ParitySans as CID TrueType while Chrome's PDF uses Type 3, so their PDF glyph programs produce slightly different edge coverage in that shared rasterization. This does not indicate missing opacity-group support; raw evidence remains reported.

regions (63 total; showing 63 representatives)

Complete component census grouped by dominant raster class; representative details are bounded.

Complete dominant-class aggregates

class	regions	pixels	union bbox (CSS px)	largest px	maximum magnitude
ColorErr	63	3804	24,30 → 141,115	900	total 1.1% · largest 0.3%

Representative region details (worst-first)

class	bbox (CSS px)	area%	magnitude	reason
AntialiasCoverage	33,53 → 141,115	0.3	ΔRGB(62,62,62)	antialiasing coverage residue on a shared outline
AntialiasCoverage	24,30 → 131,88	0.3	ΔRGB(-55,-55,-55)	antialiasing coverage residue on a shared outline
AntialiasCoverage	39,42 → 73,91	0.2	ΔRGB(12,12,12)	antialiasing coverage residue on a shared outline
AntialiasCoverage	92,57 → 127,103	0.2	ΔRGB(-23,-23,-23)	antialiasing coverage residue on a shared outline
AntialiasCoverage	80,56 → 86,89	0.09	ΔRGB(16,16,16)	antialiasing coverage residue on a shared outline
AntialiasCoverage	45,95 → 73,103	0.05	ΔRGB(-45,-45,-45)	antialiasing coverage residue on a shared outline
AntialiasCoverage	92,42 → 120,50	0.05	ΔRGB(54,54,54)	antialiasing coverage residue on a shared outline
AntialiasCoverage	97,53 → 98,57	0.004511	ΔRGB(19,19,19)	antialiasing coverage residue on a shared outline
AntialiasCoverage	124,55 → 124,58	0.003910	ΔRGB(-24,-24,-24)	antialiasing coverage residue on a shared outline
AntialiasCoverage	68,91 → 69,94	0.003910	ΔRGB(-24,-24,-24)	antialiasing coverage residue on a shared outline
AntialiasCoverage	26,88 → 27,91	0.003308	ΔRGB(-19,-19,-19)	antialiasing coverage residue on a shared outline
AntialiasCoverage	132,42 → 132,43	0.002406	ΔRGB(-11,-11,-11)	antialiasing coverage residue on a shared outline
AntialiasCoverage	84,58 → 84,60	0.002406	ΔRGB(-22,-22,-22)	antialiasing coverage residue on a shared outline
AntialiasCoverage	94,47 → 95,48	0.001805	ΔRGB(-7,-7,-7)	antialiasing coverage residue on a shared outline
AntialiasCoverage	138,52 → 138,53	0.001805	ΔRGB(31,31,31)	antialiasing coverage residue on a shared outline
AntialiasCoverage	83,57 → 84,58	0.001805	ΔRGB(-14,-14,-14)	antialiasing coverage residue on a shared outline
AntialiasCoverage	44,94 → 45,95	0.001805	ΔRGB(-17,-17,-17)	antialiasing coverage residue on a shared outline
AntialiasCoverage	32,100 → 33,101	0.001805	ΔRGB(22,22,22)	antialiasing coverage residue on a shared outline
AntialiasCoverage	137,50 → 137,51	0.001504	ΔRGB(22,22,22)	antialiasing coverage residue on a shared outline
AntialiasCoverage	97,52 → 97,53	0.001504	ΔRGB(11,11,11)	antialiasing coverage residue on a shared outline
AntialiasCoverage	28,92 → 28,93	0.001504	ΔRGB(-11,-11,-11)	antialiasing coverage residue on a shared outline
AntialiasCoverage	30,97 → 30,98	0.001504	ΔRGB(11,11,11)	antialiasing coverage residue on a shared outline
AntialiasCoverage	133,44 → 133,44	0.001203	ΔRGB(-12,-12,-12)	antialiasing coverage residue on a shared outline
AntialiasCoverage	93,46 → 94,46	0.001203	ΔRGB(-11,-11,-11)	antialiasing coverage residue on a shared outline
AntialiasCoverage	121,50 → 121,51	0.001203	ΔRGB(11,11,11)	antialiasing coverage residue on a shared outline
AntialiasCoverage	42,88 → 42,89	0.001203	ΔRGB(10,10,10)	antialiasing coverage residue on a shared outline
AntialiasCoverage	44,93 → 44,93	0.001203	ΔRGB(-12,-12,-12)	antialiasing coverage residue on a shared outline
AntialiasCoverage	31,98 → 31,99	0.001203	ΔRGB(20,20,20)	antialiasing coverage residue on a shared outline
AntialiasCoverage	31,99 → 32,100	0.001203	ΔRGB(21,21,21)	antialiasing coverage residue on a shared outline
AntialiasCoverage	27,91 → 27,92	0.000902	ΔRGB(-11,-11,-11)	antialiasing coverage residue on a shared outline
AntialiasCoverage	136,48 → 136,48	0.000602	ΔRGB(20,20,20)	antialiasing coverage residue on a shared outline
AntialiasCoverage	136,48 → 136,49	0.000602	ΔRGB(22,22,22)	antialiasing coverage residue on a shared outline
AntialiasCoverage	136,49 → 136,49	0.000602	ΔRGB(22,22,22)	antialiasing coverage residue on a shared outline
AntialiasCoverage	96,51 → 96,51	0.000602	ΔRGB(10,10,10)	antialiasing coverage residue on a shared outline
AntialiasCoverage	137,51 → 137,51	0.000602	ΔRGB(42,42,42)	antialiasing coverage residue on a shared outline
AntialiasCoverage	122,52 → 122,52	0.000602	ΔRGB(-4,-4,-4)	antialiasing coverage residue on a shared outline
AntialiasCoverage	123,53 → 123,53	0.000602	ΔRGB(-11,-11,-11)	antialiasing coverage residue on a shared outline
AntialiasCoverage	123,54 → 123,54	0.000602	ΔRGB(-12,-12,-12)	antialiasing coverage residue on a shared outline
AntialiasCoverage	123,54 → 123,55	0.000602	ΔRGB(-24,-24,-24)	antialiasing coverage residue on a shared outline
AntialiasCoverage	43,91 → 43,91	0.000602	ΔRGB(-7,-7,-7)	antialiasing coverage residue on a shared outline
AntialiasCoverage	44,92 → 44,92	0.000602	ΔRGB(-10,-10,-10)	antialiasing coverage residue on a shared outline
AntialiasCoverage	28,93 → 28,94	0.000602	ΔRGB(-5,-5,-5)	antialiasing coverage residue on a shared outline
AntialiasCoverage	69,94 → 69,94	0.000602	ΔRGB(-10,-10,-10)	antialiasing coverage residue on a shared outline
AntialiasCoverage	29,95 → 29,95	0.000602	ΔRGB(-7,-7,-7)	antialiasing coverage residue on a shared outline
AntialiasCoverage	70,95 → 70,95	0.000602	ΔRGB(-24,-24,-24)	antialiasing coverage residue on a shared outline
AntialiasCoverage	70,95 → 70,96	0.000602	ΔRGB(-10,-10,-10)	antialiasing coverage residue on a shared outline
AntialiasCoverage	70,96 → 70,96	0.000602	ΔRGB(-5,-5,-5)	antialiasing coverage residue on a shared outline
AntialiasCoverage	71,97 → 71,97	0.000602	ΔRGB(-4,-4,-4)	antialiasing coverage residue on a shared outline
AntialiasCoverage	131,42 → 131,42	0.000301	ΔRGB(-33,-33,-33)	antialiasing coverage residue on a shared outline
AntialiasCoverage	133,44 → 133,44	0.000301	ΔRGB(-10,-10,-10)	antialiasing coverage residue on a shared outline
AntialiasCoverage	134,45 → 134,45	0.000301	ΔRGB(-14,-14,-14)	antialiasing coverage residue on a shared outline
AntialiasCoverage	135,47 → 135,47	0.000301	ΔRGB(11,11,11)	antialiasing coverage residue on a shared outline
AntialiasCoverage	135,47 → 135,47	0.000301	ΔRGB(9,9,9)	antialiasing coverage residue on a shared outline
AntialiasCoverage	95,48 → 95,48	0.000301	ΔRGB(-10,-10,-10)	antialiasing coverage residue on a shared outline
AntialiasCoverage	120,50 → 120,50	0.000301	ΔRGB(26,26,26)	antialiasing coverage residue on a shared outline
AntialiasCoverage	122,53 → 122,53	0.000301	ΔRGB(-8,-8,-8)	antialiasing coverage residue on a shared outline
AntialiasCoverage	42,90 → 42,90	0.000301	ΔRGB(15,15,15)	antialiasing coverage residue on a shared outline
AntialiasCoverage	43,92 → 43,92	0.000301	ΔRGB(-18,-18,-18)	antialiasing coverage residue on a shared outline
AntialiasCoverage	29,95 → 29,95	0.000301	ΔRGB(22,22,22)	antialiasing coverage residue on a shared outline
AntialiasCoverage	29,96 → 29,96	0.000301	ΔRGB(5,5,5)	antialiasing coverage residue on a shared outline
AntialiasCoverage	30,97 → 30,97	0.000301	ΔRGB(10,10,10)	antialiasing coverage residue on a shared outline
AntialiasCoverage	71,97 → 71,97	0.000301	ΔRGB(-8,-8,-8)	antialiasing coverage residue on a shared outline
AntialiasCoverage	71,98 → 71,98	0.000301	ΔRGB(-11,-11,-11)	antialiasing coverage residue on a shared outline

source · cases/color-opacity/opacity-text-glyph-group.html

1<!DOCTYPE html>
2<html lang="en">
3<head>
4<meta charset="utf-8">
5<title>opacity text glyph group</title>
6<style>
7  @page { size: 224px 152px; margin: 0; }
8  html { font-family: ParitySans; line-height: 1.5; }
9  * { margin: 0; box-sizing: border-box; }
10  html, body { background: #000000; }
11  .stage {
12    width: 220px;
13    height: 150px;
14    overflow: hidden;
15    background: #000000;
16  }
17  .glyphs {
18    width: 220px;
19    height: 150px;
20    padding-left: 20px;
21    color: #ffffff;
22    opacity: 0.5;
23    font-size: 108px;
24    font-weight: 700;
25    line-height: 150px;
26    letter-spacing: -44px;
27    white-space: nowrap;
28  }
29</style>
30</head>
31<body>
32  <div class="stage"><div class="glyphs">OO</div></div>
33</body>
34</html>

PASS exact match opacity-half · half

Box with opacity 0.5 composited over a solid background box.

PASS exact match opacity-percentage · percentage-value

opacity:50% composites a red box at half alpha over a blue stage; catches opacity parsers that accept only numeric values.

PASS exact match opacity-var-percentage-reparses-after-substitution · var-percentage

opacity:var(--half-opacity) reparses the substituted 50% token stream using the opacity grammar, even when the custom property is declared later in the stylesheet.

CSS named color — 100.00% verified visual parity PASS 1 · FAIL 0 · REFERENCE-DISPUTED 0all categories ↑

PASS exact match r2-color-named-papayawhip · named-papayawhip

All CSS named colors must be available, not just the small legacy subset: A fixed-size color swatch isolates parsing/conversion/compositing of the color syntax. Catches wrong implementation: Parser accepts only the existing subset or drops the declaration, producing default/transparent paint.

background-color — 100.00% verified visual parity PASS 1 · FAIL 0 · REFERENCE-DISPUTED 0all categories ↑

PASS exact match r2-background-color-currentcolor · background-currentcolor

currentColor must resolve in background-color: A fixed-size color swatch isolates parsing/conversion/compositing of the color syntax. Catches wrong implementation: Parser accepts only the existing subset or drops the declaration, producing default/transparent paint.

color(display-p3 ...) — 100.00% verified visual parity PASS 1 · FAIL 0 · REFERENCE-DISPUTED 0all categories ↑

PASS exact match r2-color-function-display-p3 · color-display-p3

display-p3 colors must gamut-map to output sRGB: A fixed-size color swatch isolates parsing/conversion/compositing of the color syntax. Catches wrong implementation: Parser accepts only the existing subset or drops the declaration, producing default/transparent paint.

color(srgb ...) — 100.00% verified visual parity PASS 1 · FAIL 0 · REFERENCE-DISPUTED 0all categories ↑

PASS exact match r2-color-function-srgb · color-srgb

color(srgb ...) must parse as a predefined RGB color: A fixed-size color swatch isolates parsing/conversion/compositing of the color syntax. Catches wrong implementation: Parser accepts only the existing subset or drops the declaration, producing default/transparent paint.

color(srgb-linear ...) — 100.00% verified visual parity PASS 1 · FAIL 0 · REFERENCE-DISPUTED 0all categories ↑

PASS exact match r2-color-function-srgb-linear · color-srgb-linear

color(srgb-linear ...) must convert linear-light components: A fixed-size color swatch isolates parsing/conversion/compositing of the color syntax. Catches wrong implementation: Parser accepts only the existing subset or drops the declaration, producing default/transparent paint.

color(xyz-d65 ...) — 100.00% verified visual parity PASS 1 · FAIL 0 · REFERENCE-DISPUTED 0all categories ↑

PASS exact match r2-color-function-xyz-d65 · color-xyz-d65

XYZ predefined colors must convert to output sRGB: A fixed-size color swatch isolates parsing/conversion/compositing of the color syntax. Catches wrong implementation: Parser accepts only the existing subset or drops the declaration, producing default/transparent paint.

color-format — 100.00% verified visual parity PASS 27 · FAIL 0 · REFERENCE-DISPUTED 0all categories ↑

PASS exact match color-alpha-percentage · alpha-percentage

Percentage alpha rgb(... / 50%) composited over a solid box; css-color-4 §15.

PASS exact match color-hex-rgb · hex-3-digit

Box filled with a 3-digit shorthand hex color (#0a6).

PASS exact match color-hex-rgba · hex-4-digit

Semi-transparent 4-digit hex (#f508) composited over a solid box; css-color-4 §5.2.

PASS exact match color-hex-rrggbb · hex-6-digit

Box filled with a 6-digit hex color (#c2185b).

PASS exact match color-hex-rrggbbaa · hex-8-digit

Semi-transparent 8-digit hex (#ff572280) composited over a solid box; css-color-4 §5.2.

PASS exact match color-hsl · hsl-function

Box filled with an hsl() functional color (hsl(280 60% 45%)); css-color-4 §7.

PASS exact match color-hsl-hue-angle · hsl-hue-angle

hsl() hue with angle unit (0.5turn = 180deg); css-color-4 §7.

PASS exact match color-hsl-modern-slash · hsl-modern-slash

Modern hsl(h s l / a) slash-alpha composited over a solid box; css-color-4 §7.

PASS exact match color-hsl-powerless-hue · hsl-powerless-hue

hsl() powerless hue at 0% saturation -> gray; css-color-4 §7.

PASS exact match color-hsla-alpha · hsla-alpha

Semi-transparent hsla() box composited over a solid background; css-color-4 §7.

PASS exact match color-hwb · hwb-function

hwb(194 0% 0%) fully-saturated functional color; css-color-4 §8.

PASS exact match color-hwb-gray · hwb-gray

hwb(120 50% 50%) where whiteness+blackness=1 -> gray; css-color-4 §8.

PASS exact match color-named · named-keyword

Box filled with a named CSS color keyword (navy).

PASS exact match color-named-case-insensitive · named-case-insensitive

Named color is ASCII case-insensitive (NavY -> navy); css-color-4 §6.1.

PASS exact match color-oklch · oklch

CSS Color 4 oklch() background color converts to output sRGB; catches legacy-only parsers that drop the declaration to the fallback color.

PASS exact match color-rebeccapurple · rebeccapurple

rebeccapurple named keyword (#663399); css-color-4 §6.1.

PASS exact match color-rgb-clamp · rgb-clamp

Out-of-range rgb(300 -20 999) clamps to [0,255]; css-color-4 §11.

PASS exact match color-rgb-function · rgb-function

Box filled with an rgb() functional color.

PASS exact match color-rgb-modern-slash · rgb-modern-slash

Modern space syntax rgb(r g b / a) composited over a solid box; css-color-4 §11.

PASS exact match color-rgb-none · rgb-none

Modern rgb() with the none keyword (resolves to 0); css-color-4 §4.3.

PASS exact match color-rgb-percentage · rgb-percentage

Box filled with rgb() percentage components rgb(80% 20% 10%); css-color-4 §11.

PASS exact match color-rgba-alpha · rgba-alpha

Semi-transparent rgba() box composited (source-over) over a solid background box; css-color-4 §12.

PASS exact match color-text-glyph · text-glyph-fill

Chrome ref

ironpress

full-page >1.0%/channel diff

The color property fills text glyphs in ParitySans with a solid color.

PASS exact match opacity-clamp · opacity-clamp

opacity:1.5 clamps to 1.0 (fully opaque); computed opacity is in [0,1].

PASS exact match opacity-nested-group · opacity-nested

opacity on a group flattens then composites the whole at 0.5 (not per child).

PASS exact match opacity-zero · opacity-zero

opacity:0 fully transparent but layout space reserved; the next box flows below.

PASS exact match visibility-visible-after-hidden · visibility-visible-after-hidden

visibility:visible child paints inside a visibility:hidden parent; CSS2 §11.2.

color-keyword — 100.00% verified visual parity PASS 2 · FAIL 0 · REFERENCE-DISPUTED 0all categories ↑

PASS exact match color-currentcolor · currentcolor

currentColor resolves the color property into a thick solid border; css-color-4 §6.2.

PASS exact match color-transparent-keyword · transparent

transparent (= rgb(0 0 0 / 0)) background lets the under box show through a bordered overlay; css-color-4 §6.1.

color-mix() — 100.00% verified visual parity PASS 1 · FAIL 0 · REFERENCE-DISPUTED 0all categories ↑

PASS exact match r2-color-mix-red-blue · color-mix

color-mix() static colors must resolve before painting: A fixed-size color swatch isolates parsing/conversion/compositing of the color syntax. Catches wrong implementation: Parser accepts only the existing subset or drops the declaration, producing default/transparent paint.

display — 100.00% verified visual parity PASS 1 · FAIL 0 · REFERENCE-DISPUTED 0all categories ↑

PASS exact match display-none-removal · none-removal

display:none removes the first block entirely so the second block rises to the top of the page.

hsl() with none component — 100.00% verified visual parity PASS 1 · FAIL 0 · REFERENCE-DISPUTED 0all categories ↑

PASS exact match r2-color-hsl-none-component · hsl-none

hsl() missing components beyond rgb() must parse: A fixed-size color swatch isolates parsing/conversion/compositing of the color syntax. Catches wrong implementation: Parser accepts only the existing subset or drops the declaration, producing default/transparent paint.

hwb() with alpha — 100.00% verified visual parity PASS 1 · FAIL 0 · REFERENCE-DISPUTED 0all categories ↑

PASS exact match r2-color-hwb-alpha-over-blue · hwb-alpha

hwb() slash alpha needs coverage: A fixed-size color swatch isolates parsing/conversion/compositing of the color syntax. Catches wrong implementation: Parser accepts only the existing subset or drops the declaration, producing default/transparent paint.

lab() — 100.00% verified visual parity PASS 1 · FAIL 0 · REFERENCE-DISPUTED 0all categories ↑

PASS exact match r2-color-lab · lab

lab() colors must convert to sRGB: A fixed-size color swatch isolates parsing/conversion/compositing of the color syntax. Catches wrong implementation: Parser accepts only the existing subset or drops the declaration, producing default/transparent paint.

lch() — 100.00% verified visual parity PASS 1 · FAIL 0 · REFERENCE-DISPUTED 0all categories ↑

PASS exact match r2-color-lch · lch

lch() colors must convert to sRGB: A fixed-size color swatch isolates parsing/conversion/compositing of the color syntax. Catches wrong implementation: Parser accepts only the existing subset or drops the declaration, producing default/transparent paint.

oklab() — 100.00% verified visual parity PASS 1 · FAIL 0 · REFERENCE-DISPUTED 0all categories ↑

PASS exact match r2-color-oklab · oklab

oklab() colors must convert to sRGB: A fixed-size color swatch isolates parsing/conversion/compositing of the color syntax. Catches wrong implementation: Parser accepts only the existing subset or drops the declaration, producing default/transparent paint.

opacity group flattening with alpha child overlap — 100.00% verified visual parity PASS 1 · FAIL 0 · REFERENCE-DISPUTED 0all categories ↑

PASS exact match r2-opacity-group-flatten-alpha-overlap · opacity-group-flatten-alpha-overlap

opacity on a group with alpha children must flatten before compositing: A parent opacity:.5 contains a semitransparent red child over an opaque blue child; the group is flattened before being composited onto white. Catches wrong implementation: Renderer multiplies each child alpha independently against the page, causing a different overlap color.

opacity stacking context with z-index descendants — 100.00% verified visual parity PASS 1 · FAIL 0 · REFERENCE-DISPUTED 0all categories ↑

PASS exact match r2-opacity-stacking-context-z-index · opacity-stacking-context

opacity-created stacking contexts must contain positioned descendants: An opacity:.99 parent has a high z-index child and is followed by a sibling; the child cannot escape the parent's stacking context to cover the sibling. Catches wrong implementation: Renderer applies opacity per draw and sorts the descendant globally by z-index.

visibility — 100.00% verified visual parity PASS 2 · FAIL 0 · REFERENCE-DISPUTED 0all categories ↑

PASS exact match visibility-collapse-row · collapse-table-row

visibility:collapse on a table row removes the row and collapses its height.

PASS exact match visibility-hidden · hidden-reserves-space

visibility:hidden hides the first block but reserves its space, so the second block stays offset below.

color-opacity — 100.00% verified visual parity