#637890
Closest named color: Grey Blue (#647D8E). oklch(56.5% 0.045 252), rgb(99, 120, 144).
Aa
Black text reads best on this color (4.61:1).
About this color
#637890 is a medium-dark, muted blue. In OKLCH its lightness is 56%, its chroma 0.045 and its hue 252°. Its hue sits on the cool side of the wheel. The nearest named color is Grey Blue (#647D8E), ΔE 0.016 away. Black text reads best on it, at 4.61:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | muted (0.045) |
| Temperature | cool |
| Nearest name | Grey Blue (#647D8E) |
| Black text | 4.61:1 |
| White text | 4.54:1 |
Values
| HEX | #637890 |
| RGB | rgb(99, 120, 144) |
| HSL | hsl(212, 19%, 48%) |
| OKLCH | oklch(56.5% 0.045 252) |
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 #637890 | 4.54:1 | AA | Lc -77.0 | Fine for body text |
| Black text on #637890 | 4.61:1 | AA | Lc 32.5 | Non-text elements, placeholder text |
| #637890 text on white | 4.54:1 | AA | Lc 71.6 | Content text, not long reading |
| #637890 text on black | 4.61:1 | AA | Lc -30.1 | Non-text elements, placeholder text |
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
#F4F5F7
oklch(97% 0.003 264.5)
-
Step 100
100
#E7EAEE
oklch(93.6% 0.006 255.5)
-
Step 200
200
#D4DAE0
oklch(88.6% 0.011 247.9)
-
Step 300
300
#B8C2CE
oklch(81% 0.02 252.9)
-
Step 400
400
#92A2B5
oklch(70.6% 0.033 252.8)
-
Step 500
500
#788CA2
oklch(63.2% 0.04 250.9)
-
Step 600
600 (this color)
#637890
oklch(56.5% 0.045 252)
-
Step 700
700
#506378
oklch(49.2% 0.041 251.2)
-
Step 800
800
#415062
oklch(42.6% 0.036 253.2)
-
Step 900
900
#374350
oklch(37.8% 0.027 250.6)
-
Step 950
950
#20272F
oklch(26.9% 0.018 251.9)
#637890 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) | #6F7991 | 0.017 |
| Deuteranopia (no green cones) | #6A7490 | 0.014 |
| Tritanopia (no blue cones) | #567D80 | 0.038 |
| Achromatopsia (no color) | #767676 | 0.045 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #637890
#637890
oklch(56.5% 0.045 252)
- #877259
#877259
oklch(56.5% 0.045 71.6)
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 #637890, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Grey Blue #647D8E ΔE 0.016
- Battleship Grey #6B7C85 ΔE 0.026
- Stormy Blue #507B9C ΔE 0.027
- Battleship Gray #6C757D ΔE 0.029
- Metallic Blue #4F738E ΔE 0.031
- Slate Gray #708090 ΔE 0.031
- Cerulean #457B9D ΔE 0.037
- Dull Blue #49759C ΔE 0.038
Use #637890 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.