ColorsMine

#374151 on black

Tailwind gray-700 — roughly Charcoal — measured against black to WCAG 2.2 and APCA.

2.04:1

contrast ratio · APCA Lc 12

The quick brown fox
…and the same at 13 px
✕ Body text (AA, 4.5:1) ✕ Body text (AAA, 7:1) ✕ Large text (AA, 3:1) ✕ Borders and icons (1.4.11, 3:1)

The nearest colour that passes

Keeping the hue and moving only the lightness, #6B7788 is the closest shade to #374151 that clears 4.5:1 on black — at 4.62:1.

#374151
2.04:1 — fails
#6B7788
4.62:1 — passes

Under colour blindness

Contrast is a lightness relationship, so a ratio survives colour blindness — but the pair can still lose the distinction it was carrying. This is the same two colours as seen with each dichromacy.

VisionForegroundBackgroundRatio
Normal #374151 #000000 2.04:1
Protanopia
red-blind, ~1% of men
#3C3C4D #000000 1.95:1
Deuteranopia
green-blind, ~6% of men
#3B3A4D #000000 1.90:1
Tritanopia
blue-blind, rare
#384B4A #000000 2.27:1

What the thresholds mean

Related

Same colour on white The full gray scale

Fixing one pair is not the job

ColorsMine checks every pairing a palette implies, in light and dark, and names the single change that moves the grade most.

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