#636EBB
Closest named color: French Blue (#436BAD). oklch(56.4% 0.119 275.8), rgb(99, 110, 187).
Aa
White text reads best on this color (4.68:1).
About this color
#636EBB is a medium-dark, moderately saturated blue. In OKLCH its lightness is 56%, its chroma 0.119 and its hue 276°. Its hue sits on the cool side of the wheel. The nearest named color is French Blue (#436BAD), ΔE 0.047 away. White text reads best on it, at 4.68:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | moderately saturated (0.119) |
| Temperature | cool |
| Nearest name | French Blue (#436BAD) |
| Black text | 4.47:1 |
| White text | 4.68:1 |
Values
| HEX | #636EBB |
| RGB | rgb(99, 110, 187) |
| HSL | hsl(233, 39%, 56%) |
| OKLCH | oklch(56.4% 0.119 275.8) |
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 #636EBB | 4.68:1 | AA | Lc -77.9 | Fine for body text |
| Black text on #636EBB | 4.47:1 | AA large text | Lc 31.6 | Non-text elements, placeholder text |
| #636EBB text on white | 4.68:1 | AA | Lc 72.4 | Content text, not long reading |
| #636EBB text on black | 4.47:1 | AA large text | Lc -29.2 | 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
#F4F5FA
oklch(97.1% 0.007 277.2)
-
Step 100
100
#E7E9F5
oklch(93.6% 0.016 278.5)
-
Step 200
200
#D3D8ED
oklch(88.5% 0.029 275.1)
-
Step 300
300
#B6BEE4
oklch(80.8% 0.054 275.8)
-
Step 400
400
#919CD6
oklch(70.6% 0.086 275.7)
-
Step 500
500
#7783CB
oklch(63.1% 0.109 275.6)
-
Step 600
600 (this color)
#636EBB
oklch(56.4% 0.119 275.8)
-
Step 700
700
#50599F
oklch(49% 0.112 275.9)
-
Step 800
800
#424981
oklch(42.7% 0.093 276.3)
-
Step 900
900
#373E67
oklch(37.8% 0.071 275.1)
-
Step 950
950
#20243C
oklch(26.9% 0.045 275.7)
#636EBB 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) | #5178BE | 0.032 |
| Deuteranopia (no green cones) | #4970B9 | 0.032 |
| Tritanopia (no blue cones) | #437E8B | 0.106 |
| Achromatopsia (no color) | #747474 | 0.119 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #636EBB
#636EBB
oklch(56.4% 0.119 275.8)
- #8B7400
#8B7400
oklch(56.4% 0.116 95.1)
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 #636EBB, closest first.
No curated palette has a color within ΔE 0.04 of #636EBB.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- French Blue #436BAD ΔE 0.047
- Windows Blue #3778BF ΔE 0.050
- Dark Periwinkle #665FD1 ΔE 0.055
- Flat Blue #3C73A8 ΔE 0.058
- Iris #6258C4 ΔE 0.060
- Slate Blue #6A5ACD ΔE 0.061
- Light Indigo #6D5ACF ΔE 0.063
- Steel Blue #4682B4 ΔE 0.064
Use #636EBB 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.