#636ECD
Closest named color: Dark Periwinkle (#665FD1). oklch(57.5% 0.145 275.9), rgb(99, 110, 205).
Aa
Black text reads best on this color (4.64:1).
About this color
#636ECD is a medium-dark, vivid blue. In OKLCH its lightness is 58%, its chroma 0.145 and its hue 276°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Periwinkle (#665FD1), ΔE 0.038 away. Black text reads best on it, at 4.64:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | vivid (0.145) |
| Temperature | cool |
| Nearest name | Dark Periwinkle (#665FD1) |
| Black text | 4.64:1 |
| White text | 4.52:1 |
Values
| HEX | #636ECD |
| RGB | rgb(99, 110, 205) |
| HSL | hsl(234, 51%, 60%) |
| OKLCH | oklch(57.5% 0.145 275.9) |
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 #636ECD | 4.52:1 | AA | Lc -76.7 | Fine for body text |
| Black text on #636ECD | 4.64:1 | AA | Lc 32.9 | Non-text elements, placeholder text |
| #636ECD text on white | 4.52:1 | AA | Lc 71.2 | Content text, not long reading |
| #636ECD text on black | 4.64:1 | AA | Lc -30.5 | Non-text elements, placeholder text |
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
#E6E9F7
oklch(93.6% 0.019 276.3)
-
Step 200
200
#D2D8F2
oklch(88.6% 0.036 275.3)
-
Step 300
300
#B4BEEB
oklch(80.9% 0.065 275.1)
-
Step 400
400
#8F9BE2
oklch(70.8% 0.105 276)
-
Step 500
500
#7480D9
oklch(63% 0.134 276.1)
-
Step 600
600 (this color)
#636ECD
oklch(57.5% 0.145 275.9)
-
Step 700
700
#4D56AC
oklch(49.1% 0.136 275.7)
-
Step 800
800
#3F478B
oklch(42.7% 0.112 275.6)
-
Step 900
900
#353C6F
oklch(37.7% 0.087 275.5)
-
Step 950
950
#1F2341
oklch(26.9% 0.056 276.2)
#636ECD 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) | #447BD1 | 0.044 |
| Deuteranopia (no green cones) | #3972CB | 0.046 |
| Tritanopia (no blue cones) | #358393 | 0.129 |
| Achromatopsia (no color) | #767676 | 0.145 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #636ECD
#636ECD
oklch(57.5% 0.145 275.9)
- #8E7800
#8E7800
oklch(57.6% 0.119 96.2)
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 #636ECD, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Periwinkle #665FD1 ΔE 0.038
- Slate Blue #6A5ACD ΔE 0.049
- Light Indigo #6D5ACF ΔE 0.050
- Royal Blue #4169E1 ΔE 0.053
- Iris #6258C4 ΔE 0.055
- Windows Blue #3778BF ΔE 0.058
- Medium Slate Blue #7B68EE ΔE 0.063
- French Blue #436BAD ΔE 0.066
Use #636ECD 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.