#6366B3
Closest named color: French Blue (#436BAD). oklch(54.4% 0.119 280), rgb(99, 102, 179).
Aa
White text reads best on this color (5.14:1).
About this color
#6366B3 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 54%, its chroma 0.119 and its hue 280°. Its hue sits on the cool side of the wheel. The nearest named color is French Blue (#436BAD), ΔE 0.043 away. White text reads best on it, at 5.14:1.
| Hue family | Blues |
| Lightness | medium-dark (54%) |
| Chroma | moderately saturated (0.119) |
| Temperature | cool |
| Nearest name | French Blue (#436BAD) |
| Black text | 4.08:1 |
| White text | 5.14:1 |
Values
| HEX | #6366B3 |
| RGB | rgb(99, 102, 179) |
| HSL | hsl(238, 34%, 55%) |
| OKLCH | oklch(54.4% 0.119 280) |
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 #6366B3 | 5.14:1 | AA | Lc -80.7 | Fine for body text |
| Black text on #6366B3 | 4.08:1 | AA large text | Lc 28.7 | Dividers and decoration only |
| #6366B3 text on white | 5.14:1 | AA | Lc 75.3 | Fine for body text |
| #6366B3 text on black | 4.08:1 | AA large text | Lc -26.4 | 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
#E7E9F4
oklch(93.6% 0.015 277.8)
-
Step 200
200
#D5D7ED
oklch(88.4% 0.03 281.6)
-
Step 300
300
#B9BDE3
oklch(80.8% 0.054 280.4)
-
Step 400
400
#969BD5
oklch(70.7% 0.085 280.2)
-
Step 500
500
#7D81CA
oklch(63% 0.109 280.4)
-
Step 600
600 (this color)
#6366B3
oklch(54.4% 0.119 280)
-
Step 700
700
#55589E
oklch(49.1% 0.111 279.6)
-
Step 800
800
#464880
oklch(42.7% 0.092 280.2)
-
Step 900
900
#3A3D67
oklch(37.8% 0.071 279.3)
-
Step 950
950
#22243C
oklch(27.1% 0.045 279.3)
#6366B3 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) | #4970B6 | 0.039 |
| Deuteranopia (no green cones) | #446BB1 | 0.040 |
| Tritanopia (no blue cones) | #497684 | 0.103 |
| Achromatopsia (no color) | #6D6D6D | 0.119 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #6366B3
#6366B3
oklch(54.4% 0.119 280)
- #7F7000
#7F7000
oklch(54.2% 0.113 100)
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 #6366B3, closest first.
No curated palette has a color within ΔE 0.04 of #6366B3.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- French Blue #436BAD ΔE 0.043
- Iris #6258C4 ΔE 0.048
- Dark Periwinkle #665FD1 ΔE 0.052
- Slate Blue #6A5ACD ΔE 0.054
- Light Indigo #6D5ACF ΔE 0.057
- Flat Blue #3C73A8 ΔE 0.060
- Windows Blue #3778BF ΔE 0.063
- Mid Blue #276AB3 ΔE 0.064
Use #6366B3 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.