#21253B
Closest named color: Oxford Blue (#1B263B). oklch(27.2% 0.041 275.4), rgb(33, 37, 59).
Aa
White text reads best on this color (15.08:1).
About this color
#21253B is a dark, muted blue. In OKLCH its lightness is 27%, its chroma 0.041 and its hue 275°. Its hue sits on the cool side of the wheel. The nearest named color is Oxford Blue (#1B263B), ΔE 0.010 away. White text reads best on it, at 15.08:1.
| Hue family | Blues |
| Lightness | dark (27%) |
| Chroma | muted (0.041) |
| Temperature | cool |
| Nearest name | Oxford Blue (#1B263B) |
| Black text | 1.39:1 |
| White text | 15.08:1 |
Values
| HEX | #21253B |
| RGB | rgb(33, 37, 59) |
| HSL | hsl(231, 28%, 18%) |
| OKLCH | oklch(27.2% 0.041 275.4) |
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 #21253B | 15.08:1 | AAA | Lc -104.7 | Preferred for body text |
| Black text on #21253B | 1.39:1 | Fails | Lc 0.0 | Not readable |
| #21253B text on white | 15.08:1 | AAA | Lc 101.9 | Preferred for body text |
| #21253B text on black | 1.39:1 | 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 950.
-
Step 50
50
#F4F5FA
oklch(97.1% 0.007 277.2)
-
Step 100
100
#E7E9F4
oklch(93.6% 0.015 277.8)
-
Step 200
200
#D4D8EC
oklch(88.5% 0.028 276.8)
-
Step 300
300
#B7BFE1
oklch(81% 0.049 274.8)
-
Step 400
400
#929DD2
oklch(70.7% 0.079 275.1)
-
Step 500
500
#7884C6
oklch(63.1% 0.1 275.3)
-
Step 600
600
#626DB2
oklch(55.7% 0.108 275.5)
-
Step 700
700
#515B99
oklch(49.2% 0.1 275.2)
-
Step 800
800
#424A7C
oklch(42.6% 0.083 275.4)
-
Step 900
900
#383E64
oklch(37.7% 0.065 276)
-
Step 950
950 (this color)
#21253B
oklch(27.2% 0.041 275.4)
#21253B 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) | #1E273C | 0.008 |
| Deuteranopia (no green cones) | #1C253A | 0.008 |
| Tritanopia (no blue cones) | #19292D | 0.036 |
| Achromatopsia (no color) | #262626 | 0.041 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21253B
#21253B
oklch(27.2% 0.041 275.4)
- #2D270D
#2D270D
oklch(27.3% 0.042 96.5)
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 #21253B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Oxford Blue #1B263B ΔE 0.010
- Dark #1B2431 ΔE 0.022
- Space Cadet #2B2D42 ΔE 0.034
- Jet #212529 ΔE 0.034
- Gunmetal #293241 ΔE 0.046
- Rich Black #0D1B2A ΔE 0.056
- Prussian Blue #1D3557 ΔE 0.064
- Marine #042E60 ΔE 0.071
Use #21253B 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.