#637ABA
Closest named color: Cool Blue (#4984B8). oklch(58.9% 0.102 268.2), rgb(99, 122, 186).
Aa
Black text reads best on this color (5.02:1).
About this color
#637ABA is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.102 and its hue 268°. Its hue sits on the cool side of the wheel. The nearest named color is Cool Blue (#4984B8), ΔE 0.038 away. Black text reads best on it, at 5.02:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.102) |
| Temperature | cool |
| Nearest name | Cool Blue (#4984B8) |
| Black text | 5.02:1 |
| White text | 4.18:1 |
Values
| HEX | #637ABA |
| RGB | rgb(99, 122, 186) |
| HSL | hsl(224, 39%, 56%) |
| OKLCH | oklch(58.9% 0.102 268.2) |
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 #637ABA | 4.18:1 | AA large text | Lc -74.2 | Content text, not long reading |
| Black text on #637ABA | 5.02:1 | AA | Lc 35.4 | Non-text elements, placeholder text |
| #637ABA text on white | 4.18:1 | AA large text | Lc 68.7 | Content text, not long reading |
| #637ABA text on black | 5.02:1 | AA | Lc -32.9 | 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
#F4F5FA
oklch(97.1% 0.007 277.2)
-
Step 100
100
#E6EAF3
oklch(93.7% 0.013 266.7)
-
Step 200
200
#D2D9EB
oklch(88.5% 0.026 268.8)
-
Step 300
300
#B4C0DF
oklch(80.9% 0.046 268.6)
-
Step 400
400
#8D9FCF
oklch(70.6% 0.073 268.5)
-
Step 500
500
#7187C3
oklch(63.1% 0.094 268.2)
-
Step 600
600 (this color)
#637ABA
oklch(58.9% 0.102 268.2)
-
Step 700
700
#4A5E97
oklch(49.2% 0.095 268.2)
-
Step 800
800
#3D4D7A
oklch(42.8% 0.078 268.2)
-
Step 900
900
#344062
oklch(37.7% 0.061 268.6)
-
Step 950
950
#1E263A
oklch(27.1% 0.039 267.1)
#637ABA 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) | #6280BD | 0.016 |
| Deuteranopia (no green cones) | #5A78B9 | 0.013 |
| Tritanopia (no blue cones) | #428791 | 0.091 |
| Achromatopsia (no color) | #7C7C7C | 0.102 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #637ABA
#637ABA
oklch(58.9% 0.102 268.2)
- #96792A
#96792A
oklch(58.9% 0.102 88.3)
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 #637ABA, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cool Blue #4984B8 ΔE 0.038
- Steel Blue #4682B4 ΔE 0.039
- Off Blue #5684AE ΔE 0.040
- Dusty Blue #5A86AD ΔE 0.045
- Windows Blue #3778BF ΔE 0.047
- Faded Blue #658CBB ΔE 0.051
- Stormy Blue #507B9C ΔE 0.055
- Flat Blue #3C73A8 ΔE 0.057
Use #637ABA 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.