#637FA0
Closest named color: Dusty Blue (#5A86AD). oklch(58.8% 0.06 252.9), rgb(99, 127, 160).
Aa
Black text reads best on this color (5.07:1).
About this color
#637FA0 is a medium-dark, muted blue. In OKLCH its lightness is 59%, its chroma 0.060 and its hue 253°. Its hue sits on the cool side of the wheel. The nearest named color is Dusty Blue (#5A86AD), ΔE 0.025 away. Black text reads best on it, at 5.07:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | muted (0.060) |
| Temperature | cool |
| Nearest name | Dusty Blue (#5A86AD) |
| Black text | 5.07:1 |
| White text | 4.13:1 |
Values
| HEX | #637FA0 |
| RGB | rgb(99, 127, 160) |
| HSL | hsl(212, 24%, 51%) |
| OKLCH | oklch(58.8% 0.06 252.9) |
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 #637FA0 | 4.13:1 | AA large text | Lc -73.9 | Content text, not long reading |
| Black text on #637FA0 | 5.07:1 | AA | Lc 35.6 | Non-text elements, placeholder text |
| #637FA0 text on white | 4.13:1 | AA large text | Lc 68.4 | Content text, not long reading |
| #637FA0 text on black | 5.07:1 | AA | Lc -33.2 | 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
#F4F6F8
oklch(97.2% 0.003 247.9)
-
Step 100
100
#E6EAEF
oklch(93.5% 0.008 253.9)
-
Step 200
200
#D2DAE3
oklch(88.5% 0.015 251.2)
-
Step 300
300
#B5C2D2
oklch(80.9% 0.027 253.6)
-
Step 400
400
#8EA3BC
oklch(70.8% 0.044 252.9)
-
Step 500
500
#728CAB
oklch(63.1% 0.056 253.1)
-
Step 600
600 (this color)
#637FA0
oklch(58.8% 0.06 252.9)
-
Step 700
700
#4A6380
oklch(49.2% 0.056 252.6)
-
Step 800
800
#3D5168
oklch(42.8% 0.046 252.4)
-
Step 900
900
#344355
oklch(37.7% 0.037 253.3)
-
Step 950
950
#1F2732
oklch(27% 0.024 256.4)
#637FA0 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) | #7380A2 | 0.022 |
| Deuteranopia (no green cones) | #6B7A9F | 0.016 |
| Tritanopia (no blue cones) | #4F868A | 0.052 |
| Achromatopsia (no color) | #7D7D7D | 0.060 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #637FA0
#637FA0
oklch(58.8% 0.06 252.9)
- #937754
#937754
oklch(58.7% 0.061 72.4)
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 #637FA0, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusty Blue #5A86AD ΔE 0.025
- Off Blue #5684AE ΔE 0.025
- Grey Blue #647D8E ΔE 0.027
- Stormy Blue #507B9C ΔE 0.027
- Slate Gray #708090 ΔE 0.030
- Steel #738595 ΔE 0.035
- Lavender Gray #7E7F9A ΔE 0.037
- Cerulean #457B9D ΔE 0.038
Use #637FA0 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.