#6366B5
Closest named color: French Blue (#436BAD). oklch(54.5% 0.122 279.9), rgb(99, 102, 181).
Aa
White text reads best on this color (5.12:1).
About this color
#6366B5 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 54%, its chroma 0.122 and its hue 280°. Its hue sits on the cool side of the wheel. The nearest named color is French Blue (#436BAD), ΔE 0.044 away. White text reads best on it, at 5.12:1.
| Hue family | Blues |
| Lightness | medium-dark (54%) |
| Chroma | moderately saturated (0.122) |
| Temperature | cool |
| Nearest name | French Blue (#436BAD) |
| Black text | 4.09:1 |
| White text | 5.12:1 |
Values
| HEX | #6366B5 |
| RGB | rgb(99, 102, 181) |
| HSL | hsl(238, 36%, 55%) |
| OKLCH | oklch(54.5% 0.122 279.9) |
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 #6366B5 | 5.12:1 | AA | Lc -80.6 | Fine for body text |
| Black text on #6366B5 | 4.09:1 | AA large text | Lc 28.9 | Dividers and decoration only |
| #6366B5 text on white | 5.12:1 | AA | Lc 75.2 | Fine for body text |
| #6366B5 text on black | 4.09:1 | AA large text | Lc -26.5 | 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
#D5D7EE
oklch(88.5% 0.032 281.8)
-
Step 300
300
#B9BDE4
oklch(80.8% 0.055 280.5)
-
Step 400
400
#959BD7
oklch(70.7% 0.088 279.5)
-
Step 500
500
#7C81CC
oklch(63.1% 0.112 279.7)
-
Step 600
600 (this color)
#6366B5
oklch(54.5% 0.122 279.9)
-
Step 700
700
#55579F
oklch(49% 0.114 280.1)
-
Step 800
800
#454881
oklch(42.7% 0.094 279.4)
-
Step 900
900
#3A3D67
oklch(37.8% 0.071 279.3)
-
Step 950
950
#22243D
oklch(27.1% 0.046 279.3)
#6366B5 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) | #4871B8 | 0.041 |
| Deuteranopia (no green cones) | #426BB3 | 0.042 |
| Tritanopia (no blue cones) | #477685 | 0.105 |
| Achromatopsia (no color) | #6E6E6E | 0.122 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #6366B5
#6366B5
oklch(54.5% 0.122 279.9)
- #807100
#807100
oklch(54.6% 0.114 100.1)
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 #6366B5, closest first.
No curated palette has a color within ΔE 0.04 of #6366B5.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- French Blue #436BAD ΔE 0.044
- Iris #6258C4 ΔE 0.046
- Dark Periwinkle #665FD1 ΔE 0.049
- Slate Blue #6A5ACD ΔE 0.052
- Light Indigo #6D5ACF ΔE 0.055
- Flat Blue #3C73A8 ΔE 0.062
- Windows Blue #3778BF ΔE 0.062
- Mid Blue #276AB3 ΔE 0.064
Use #6366B5 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.