#636BD0
Closest named color: Dark Periwinkle (#665FD1). oklch(57.1% 0.153 277), rgb(99, 107, 208).
Aa
White text reads best on this color (4.62:1).
About this color
#636BD0 is a medium-dark, vivid blue. In OKLCH its lightness is 57%, its chroma 0.153 and its hue 277°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Periwinkle (#665FD1), ΔE 0.030 away. White text reads best on it, at 4.62:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | vivid (0.153) |
| Temperature | cool |
| Nearest name | Dark Periwinkle (#665FD1) |
| Black text | 4.54:1 |
| White text | 4.62:1 |
Values
| HEX | #636BD0 |
| RGB | rgb(99, 107, 208) |
| HSL | hsl(236, 54%, 60%) |
| OKLCH | oklch(57.1% 0.153 277) |
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 #636BD0 | 4.62:1 | AA | Lc -77.3 | Fine for body text |
| Black text on #636BD0 | 4.54:1 | AA | Lc 32.2 | Non-text elements, placeholder text |
| #636BD0 text on white | 4.62:1 | AA | Lc 71.9 | Content text, not long reading |
| #636BD0 text on black | 4.54:1 | AA | Lc -29.8 | 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
#E6E9F8
oklch(93.6% 0.02 276.9)
-
Step 200
200
#D2D7F3
oklch(88.4% 0.039 277.6)
-
Step 300
300
#B5BDEE
oklch(80.9% 0.07 277.5)
-
Step 400
400
#8F9AE5
oklch(70.7% 0.11 276.8)
-
Step 500
500
#757FDD
oklch(63.1% 0.141 277)
-
Step 600
600 (this color)
#636BD0
oklch(57.1% 0.153 277)
-
Step 700
700
#4F54AF
oklch(49% 0.142 277.4)
-
Step 800
800
#40468E
oklch(42.8% 0.117 276.6)
-
Step 900
900
#363B71
oklch(37.6% 0.092 277.1)
-
Step 950
950
#202342
oklch(27% 0.057 277.6)
#636BD0 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) | #3C79D4 | 0.051 |
| Deuteranopia (no green cones) | #2F71CE | 0.055 |
| Tritanopia (no blue cones) | #338193 | 0.135 |
| Achromatopsia (no color) | #757575 | 0.154 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #636BD0
#636BD0
oklch(57.1% 0.153 277)
- #8C7700
#8C7700
oklch(57.2% 0.118 96.7)
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 #636BD0, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Periwinkle #665FD1 ΔE 0.030
- Slate Blue #6A5ACD ΔE 0.041
- Light Indigo #6D5ACF ΔE 0.042
- Royal Blue #4169E1 ΔE 0.048
- Iris #6258C4 ΔE 0.049
- Medium Slate Blue #7B68EE ΔE 0.058
- Windows Blue #3778BF ΔE 0.064
- Warm Blue #4B57DB ΔE 0.065
Use #636BD0 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.