#6366BE
Closest named color: Dark Periwinkle (#665FD1). oklch(55% 0.135 279.5), rgb(99, 102, 190).
Aa
White text reads best on this color (5.03:1).
About this color
#6366BE is a medium-dark, moderately saturated blue. In OKLCH its lightness is 55%, its chroma 0.135 and its hue 280°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Periwinkle (#665FD1), ΔE 0.036 away. White text reads best on it, at 5.03:1.
| Hue family | Blues |
| Lightness | medium-dark (55%) |
| Chroma | moderately saturated (0.135) |
| Temperature | cool |
| Nearest name | Dark Periwinkle (#665FD1) |
| Black text | 4.17:1 |
| White text | 5.03:1 |
Values
| HEX | #6366BE |
| RGB | rgb(99, 102, 190) |
| HSL | hsl(238, 41%, 57%) |
| OKLCH | oklch(55% 0.135 279.5) |
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 #6366BE | 5.03:1 | AA | Lc -80.0 | Fine for body text |
| Black text on #6366BE | 4.17:1 | AA large text | Lc 29.5 | Dividers and decoration only |
| #6366BE text on white | 5.03:1 | AA | Lc 74.6 | Content text, not long reading |
| #6366BE text on black | 4.17:1 | AA large text | Lc -27.1 | 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
#F4F5FB
oklch(97.1% 0.008 278.6)
-
Step 100
100
#E7E9F6
oklch(93.6% 0.018 279.1)
-
Step 200
200
#D4D7F0
oklch(88.5% 0.034 280.2)
-
Step 300
300
#B8BDE8
oklch(80.9% 0.061 279.7)
-
Step 400
400
#949ADC
oklch(70.7% 0.097 279.6)
-
Step 500
500
#7B80D3
oklch(63.2% 0.124 279.6)
-
Step 600
600 (this color)
#6366BE
oklch(55% 0.135 279.5)
-
Step 700
700
#5456A6
oklch(49.2% 0.126 279.6)
-
Step 800
800
#444786
oklch(42.7% 0.103 279)
-
Step 900
900
#393C6B
oklch(37.7% 0.08 279.1)
-
Step 950
950
#21233F
oklch(26.9% 0.052 279.2)
#6366BE 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) | #4172C1 | 0.047 |
| Deuteranopia (no green cones) | #3A6CBC | 0.049 |
| Tritanopia (no blue cones) | #427989 | 0.118 |
| Achromatopsia (no color) | #6F6F6F | 0.135 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #6366BE
#6366BE
oklch(55% 0.135 279.5)
- #827200
#827200
oklch(55% 0.114 99.5)
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 #6366BE, closest first.
No curated palette has a color within ΔE 0.04 of #6366BE.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Periwinkle #665FD1 ΔE 0.036
- Iris #6258C4 ΔE 0.038
- Slate Blue #6A5ACD ΔE 0.040
- Light Indigo #6D5ACF ΔE 0.043
- French Blue #436BAD ΔE 0.051
- Windows Blue #3778BF ΔE 0.063
- Royal Blue #4169E1 ΔE 0.065
- Mid Blue #276AB3 ΔE 0.068
Use #6366BE 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.