#21356E
Closest named color: Marine Blue (#01386A). oklch(34.6% 0.102 266.5), rgb(33, 53, 110).
Aa
White text reads best on this color (11.67:1).
About this color
#21356E is a dark, moderately saturated blue. In OKLCH its lightness is 35%, its chroma 0.102 and its hue 267°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.026 away. White text reads best on it, at 11.67:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | moderately saturated (0.102) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.79:1 |
| White text | 11.67:1 |
Values
| HEX | #21356E |
| RGB | rgb(33, 53, 110) |
| HSL | hsl(224, 54%, 28%) |
| OKLCH | oklch(34.6% 0.102 266.5) |
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 #21356E | 11.67:1 | AAA | Lc -100.2 | Preferred for body text |
| Black text on #21356E | 1.79:1 | Fails | Lc 7.3 | Not readable |
| #21356E text on white | 11.67:1 | AAA | Lc 96.6 | Preferred for body text |
| #21356E text on black | 1.79:1 | Fails | Lc 0.0 | Not readable |
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 900.
-
Step 50
50
#F2F5FD
oklch(97% 0.011 269.6)
-
Step 100
100
#E3EAF9
oklch(93.6% 0.022 265.8)
-
Step 200
200
#CCD9F6
oklch(88.5% 0.042 266.3)
-
Step 300
300
#AAC0F3
oklch(80.9% 0.076 266.5)
-
Step 400
400
#7D9EED
oklch(70.7% 0.122 266.1)
-
Step 500
500
#5E83E7
oklch(63.1% 0.156 266.7)
-
Step 600
600
#456AD6
oklch(55.6% 0.171 266.6)
-
Step 700
700
#3758B9
oklch(49.1% 0.158 266.4)
-
Step 800
800
#2E4896
oklch(42.6% 0.132 266.8)
-
Step 900
900 (this color)
#21356E
oklch(34.6% 0.102 266.5)
-
Step 950
950
#182446
oklch(26.9% 0.065 267.3)
#21356E 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) | #163C70 | 0.021 |
| Deuteranopia (no green cones) | #02356D | 0.025 |
| Tritanopia (no blue cones) | #00424C | 0.084 |
| Achromatopsia (no color) | #383838 | 0.102 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21356E
#21356E
oklch(34.6% 0.102 266.5)
- #4A3600
#4A3600
oklch(34.6% 0.071 85.5)
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 #21356E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.026
- Prussian Blue #1D3557 ΔE 0.041
- Twilight Blue #0A437A ΔE 0.043
- Marine #042E60 ΔE 0.044
- Dark Blue Grey #1F3B4D ΔE 0.065
- Dark Grey Blue #29465B ΔE 0.070
- Midnight Green #073B4C ΔE 0.071
- Midnight Blue #191970 ΔE 0.073
Use #21356E 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.