#6366BB
Closest named color: Iris (#6258C4). oklch(54.8% 0.13 279.7), rgb(99, 102, 187).
Aa
White text reads best on this color (5.06:1).
About this color
#6366BB is a medium-dark, moderately saturated blue. In OKLCH its lightness is 55%, its chroma 0.130 and its hue 280°. Its hue sits on the cool side of the wheel. The nearest named color is Iris (#6258C4), ΔE 0.040 away. White text reads best on it, at 5.06:1.
| Hue family | Blues |
| Lightness | medium-dark (55%) |
| Chroma | moderately saturated (0.130) |
| Temperature | cool |
| Nearest name | Iris (#6258C4) |
| Black text | 4.14:1 |
| White text | 5.06:1 |
Values
| HEX | #6366BB |
| RGB | rgb(99, 102, 187) |
| HSL | hsl(238, 39%, 56%) |
| OKLCH | oklch(54.8% 0.13 279.7) |
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 #6366BB | 5.06:1 | AA | Lc -80.2 | Fine for body text |
| Black text on #6366BB | 4.14:1 | AA large text | Lc 29.3 | Dividers and decoration only |
| #6366BB text on white | 5.06:1 | AA | Lc 74.8 | Content text, not long reading |
| #6366BB text on black | 4.14:1 | AA large text | Lc -26.9 | 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
#E7E9F5
oklch(93.6% 0.016 278.5)
-
Step 200
200
#D4D7EF
oklch(88.4% 0.033 280)
-
Step 300
300
#B8BDE7
oklch(80.9% 0.059 279.7)
-
Step 400
400
#949ADA
oklch(70.6% 0.094 279.6)
-
Step 500
500
#7B80D0
oklch(63% 0.12 279.7)
-
Step 600
600 (this color)
#6366BB
oklch(54.8% 0.13 279.7)
-
Step 700
700
#5456A3
oklch(49% 0.121 279.8)
-
Step 800
800
#454784
oklch(42.7% 0.1 279.9)
-
Step 900
900
#3A3C6A
oklch(37.7% 0.078 280.1)
-
Step 950
950
#22233E
oklch(26.9% 0.05 280.9)
#6366BB 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) | #4472BE | 0.045 |
| Deuteranopia (no green cones) | #3D6BB9 | 0.046 |
| Tritanopia (no blue cones) | #447887 | 0.114 |
| Achromatopsia (no color) | #6E6E6E | 0.131 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #6366BB
#6366BB
oklch(54.8% 0.13 279.7)
- #817200
#817200
oklch(54.9% 0.114 100.2)
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 #6366BB, closest first.
No curated palette has a color within ΔE 0.04 of #6366BB.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Iris #6258C4 ΔE 0.040
- Dark Periwinkle #665FD1 ΔE 0.041
- Slate Blue #6A5ACD ΔE 0.044
- Light Indigo #6D5ACF ΔE 0.047
- French Blue #436BAD ΔE 0.048
- Windows Blue #3778BF ΔE 0.062
- Mid Blue #276AB3 ΔE 0.066
- Flat Blue #3C73A8 ΔE 0.067
Use #6366BB 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.