#637571
Closest named color: Battleship Gray (#6C757D). oklch(54.6% 0.022 180.5), rgb(99, 117, 113).
Aa
White text reads best on this color (4.86:1).
About this color
#637571 is a medium-dark close to neutral grey. In OKLCH its lightness is 55%, its chroma 0.022. It has too little chroma to lean warm or cool. The nearest named color is Battleship Gray (#6C757D), ΔE 0.024 away. White text reads best on it, at 4.86:1.
| Hue family | Neutrals |
| Lightness | medium-dark (55%) |
| Chroma | close to neutral grey (0.022) |
| Temperature | neutral |
| Nearest name | Battleship Gray (#6C757D) |
| Black text | 4.31:1 |
| White text | 4.86:1 |
Values
| HEX | #637571 |
| RGB | rgb(99, 117, 113) |
| HSL | hsl(167, 8%, 42%) |
| OKLCH | oklch(54.6% 0.022 180.5) |
Contrast
WCAG 2 contrast ratios are the conformance target: AA needs 4.5:1 for body text and 3:1 for large text, AAA needs 7:1. APCA Lc values are supplementary guidance from the WCAG 3 drafts.
| Pair | WCAG 2 | Result | APCA | APCA guidance |
|---|---|---|---|---|
| White text on #637571 | 4.86:1 | AA | Lc -79.2 | Fine for body text |
| Black text on #637571 | 4.31:1 | AA large text | Lc 30.3 | Non-text elements, placeholder text |
| #637571 text on white | 4.86:1 | AA | Lc 73.8 | Content text, not long reading |
| #637571 text on black | 4.31:1 | AA large text | Lc -27.9 | Dividers and decoration only |
Tints and shades
A 50–950 scale built in OKLCH: the hue is held, lightness follows a Tailwind v4-like curve, and every step is kept inside the sRGB gamut. This color sits at step 600.
-
Step 50
50
#F4F6F5
oklch(97.1% 0.002 165.1)
-
Step 100
100
#E8EAEA
oklch(93.6% 0.002 197.1)
-
Step 200
200
#D5DAD9
oklch(88.4% 0.006 183)
-
Step 300
300
#BAC3C1
oklch(81% 0.01 181.3)
-
Step 400
400
#96A4A1
oklch(70.7% 0.016 181.6)
-
Step 500
500
#7D8E8A
oklch(63.2% 0.02 179.9)
-
Step 600
600 (this color)
#637571
oklch(54.6% 0.022 180.5)
-
Step 700
700
#546561
oklch(49.1% 0.022 179.5)
-
Step 800
800
#45524F
oklch(42.6% 0.017 180)
-
Step 900
900
#3A4442
oklch(37.7% 0.014 182.2)
-
Step 950
950
#222827
oklch(27.1% 0.009 184.6)
#637571 with color blindness
Simulated with the Machado et al. (2009) model. ΔE is how far the color moves: below about 0.02 you would not notice a change.
| Vision | Seen as | Shift (ΔE) |
|---|---|---|
| Protanopia (no red cones) | #737371 | 0.023 |
| Deuteranopia (no green cones) | #707071 | 0.023 |
| Tritanopia (no blue cones) | #5F7674 | 0.006 |
| Achromatopsia (no color) | #717171 | 0.022 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #637571
#637571
oklch(54.6% 0.022 180.5)
- #7C6B70
#7C6B70
oklch(54.5% 0.023 358.2)
Analogous
Neighbouring hues, 30° either side.
Split complementary
The two hues beside the complement (150° and 210°).
Triadic
Three hues spaced 120° apart.
Palettes with this color
Curated palettes that contain a color within ΔE 0.04 (OKLab) of #637571, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Battleship Gray #6C757D ΔE 0.024
- Dim Gray #696969 ΔE 0.034
- Battleship Grey #6B7C85 ΔE 0.035
- Grey Blue #647D8E ΔE 0.045
- Steel Grey #6F828A ΔE 0.051
- Medium Grey #7D7F7C ΔE 0.051
- Metallic Blue #4F738E ΔE 0.053
- Grey Brown #7F7053 ΔE 0.054
Use #637571 in your product
Turn it into light and dark UI roles checked for contrast, then export to Tailwind v4, shadcn/ui, CSS or design tokens.