#6366D5
Closest named color: Dark Periwinkle (#665FD1). oklch(56.5% 0.167 278.5), rgb(99, 102, 213).
Aa
White text reads best on this color (4.78:1).
About this color
#6366D5 is a medium-dark, vivid blue. In OKLCH its lightness is 57%, its chroma 0.167 and its hue 278°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Periwinkle (#665FD1), ΔE 0.017 away. White text reads best on it, at 4.78:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | vivid (0.167) |
| Temperature | cool |
| Nearest name | Dark Periwinkle (#665FD1) |
| Black text | 4.39:1 |
| White text | 4.78:1 |
Values
| HEX | #6366D5 |
| RGB | rgb(99, 102, 213) |
| HSL | hsl(238, 58%, 61%) |
| OKLCH | oklch(56.5% 0.167 278.5) |
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 #6366D5 | 4.78:1 | AA | Lc -78.4 | Fine for body text |
| Black text on #6366D5 | 4.39:1 | AA large text | Lc 31.2 | Non-text elements, placeholder text |
| #6366D5 text on white | 4.78:1 | AA | Lc 72.9 | Content text, not long reading |
| #6366D5 text on black | 4.39:1 | AA large text | Lc -28.8 | 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
#F4F5FC
oklch(97.1% 0.009 279.7)
-
Step 100
100
#E6E9F9
oklch(93.6% 0.022 277.5)
-
Step 200
200
#D2D7F5
oklch(88.5% 0.042 278)
-
Step 300
300
#B5BCF1
oklch(80.8% 0.075 278.7)
-
Step 400
400
#9098EA
oklch(70.6% 0.12 278.6)
-
Step 500
500
#767CE4
oklch(63% 0.154 278.5)
-
Step 600
600 (this color)
#6366D5
oklch(56.5% 0.167 278.5)
-
Step 700
700
#5051B6
oklch(49% 0.156 278.5)
-
Step 800
800
#414393
oklch(42.6% 0.129 278.3)
-
Step 900
900
#373A75
oklch(37.8% 0.099 278.3)
-
Step 950
950
#202245
oklch(27% 0.064 278.7)
#6366D5 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) | #2977D9 | 0.065 |
| Deuteranopia (no green cones) | #176ED3 | 0.069 |
| Tritanopia (no blue cones) | #2E7F94 | 0.145 |
| Achromatopsia (no color) | #727272 | 0.167 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #6366D5
#6366D5
oklch(56.5% 0.167 278.5)
- #887600
#887600
oklch(56.5% 0.117 98.6)
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 #6366D5, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Periwinkle #665FD1 ΔE 0.017
- Slate Blue #6A5ACD ΔE 0.030
- Light Indigo #6D5ACF ΔE 0.031
- Iris #6258C4 ΔE 0.041
- Royal Blue #4169E1 ΔE 0.043
- Medium Slate Blue #7B68EE ΔE 0.053
- Warm Blue #4B57DB ΔE 0.053
- Neon Blue #4361EE ΔE 0.057
Use #6366D5 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.