#636CAC
Closest named color: French Blue (#436BAD). oklch(55.2% 0.1 276.5), rgb(99, 108, 172).
Aa
White text reads best on this color (4.91:1).
About this color
#636CAC is a medium-dark, moderately saturated blue. In OKLCH its lightness is 55%, its chroma 0.100 and its hue 277°. Its hue sits on the cool side of the wheel. The nearest named color is French Blue (#436BAD), ΔE 0.040 away. White text reads best on it, at 4.91:1.
| Hue family | Blues |
| Lightness | medium-dark (55%) |
| Chroma | moderately saturated (0.100) |
| Temperature | cool |
| Nearest name | French Blue (#436BAD) |
| Black text | 4.27:1 |
| White text | 4.91:1 |
Values
| HEX | #636CAC |
| RGB | rgb(99, 108, 172) |
| HSL | hsl(233, 31%, 53%) |
| OKLCH | oklch(55.2% 0.1 276.5) |
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 #636CAC | 4.91:1 | AA | Lc -79.4 | Fine for body text |
| Black text on #636CAC | 4.27:1 | AA large text | Lc 30.1 | Non-text elements, placeholder text |
| #636CAC text on white | 4.91:1 | AA | Lc 74.0 | Content text, not long reading |
| #636CAC text on black | 4.27:1 | AA large text | Lc -27.7 | 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
#E7E9F3
oklch(93.5% 0.014 277.1)
-
Step 200
200
#D4D8EA
oklch(88.5% 0.025 275.9)
-
Step 300
300
#B8BFDE
oklch(80.9% 0.044 275.3)
-
Step 400
400
#949DCE
oklch(70.7% 0.072 276.3)
-
Step 500
500
#7B84C1
oklch(63.1% 0.092 277)
-
Step 600
600 (this color)
#636CAC
oklch(55.2% 0.1 276.5)
-
Step 700
700
#535B95
oklch(49.1% 0.093 276.4)
-
Step 800
800
#444B79
oklch(42.8% 0.077 276.1)
-
Step 900
900
#393E61
oklch(37.6% 0.06 276.9)
-
Step 950
950
#212539
oklch(27% 0.038 274.9)
#636CAC 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) | #5674AF | 0.025 |
| Deuteranopia (no green cones) | #506EAB | 0.025 |
| Tritanopia (no blue cones) | #4C7984 | 0.088 |
| Achromatopsia (no color) | #707070 | 0.100 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #636CAC
#636CAC
oklch(55.2% 0.1 276.5)
- #837221
#837221
oklch(55.3% 0.1 96.9)
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 #636CAC, closest first.
No curated palette has a color within ΔE 0.04 of #636CAC.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- French Blue #436BAD ΔE 0.040
- Flat Blue #3C73A8 ΔE 0.048
- Dull Blue #49759C ΔE 0.051
- Muted Blue #3B719F ΔE 0.054
- Windows Blue #3778BF ΔE 0.056
- Dark Lavender #856798 ΔE 0.059
- Stormy Blue #507B9C ΔE 0.059
- Cerulean #457B9D ΔE 0.063
Use #636CAC 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.