#00233B
Closest named color: Oxford Blue (#1B263B). oklch(24.6% 0.06 243.5), rgb(0, 35, 59).
Aa
White text reads best on this color (16.10:1).
About this color
#00233B is a very dark, muted blue. In OKLCH its lightness is 25%, its chroma 0.060 and its hue 244°. Its hue sits on the cool side of the wheel. The nearest named color is Oxford Blue (#1B263B), ΔE 0.033 away. White text reads best on it, at 16.10:1.
| Hue family | Blues |
| Lightness | very dark (25%) |
| Chroma | muted (0.060) |
| Temperature | cool |
| Nearest name | Oxford Blue (#1B263B) |
| Black text | 1.30:1 |
| White text | 16.10:1 |
Values
| HEX | #00233B |
| RGB | rgb(0, 35, 59) |
| HSL | hsl(204, 100%, 12%) |
| OKLCH | oklch(24.6% 0.06 243.5) |
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 #00233B | 16.10:1 | AAA | Lc -105.4 | Preferred for body text |
| Black text on #00233B | 1.30:1 | Fails | Lc 0.0 | Not readable |
| #00233B text on white | 16.10:1 | AAA | Lc 102.8 | Preferred for body text |
| #00233B text on black | 1.30:1 | 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
#F0F6FC
oklch(97% 0.01 247.9)
-
Step 100
100
#DFECF7
oklch(93.7% 0.02 243.4)
-
Step 200
200
#C4DDF2
oklch(88.6% 0.039 243.5)
-
Step 300
300
#99C7EC
oklch(81% 0.072 243)
-
Step 400
400
#5CA8E2
oklch(70.7% 0.114 243.5)
-
Step 500
500
#1C91DA
oklch(63.2% 0.146 243.4)
-
Step 600
600
#007ABC
oklch(55.7% 0.136 243.3)
-
Step 700
700
#00669F
oklch(49.1% 0.12 243.6)
-
Step 800
800
#005383
oklch(42.6% 0.105 243.8)
-
Step 900
900
#00456E
oklch(37.6% 0.092 243.7)
-
Step 950
950 (this color)
#00233B
oklch(24.6% 0.06 243.5)
#00233B 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) | #17243C | 0.026 |
| Deuteranopia (no green cones) | #0E1F3B | 0.018 |
| Tritanopia (no blue cones) | #00292C | 0.041 |
| Achromatopsia (no color) | #212121 | 0.060 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #00233B
#00233B
oklch(24.6% 0.06 243.5)
- #331A00
#331A00
oklch(24.7% 0.056 63.8)
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 #00233B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Oxford Blue #1B263B ΔE 0.033
- Dark #1B2431 ΔE 0.036
- Rich Black #0D1B2A ΔE 0.038
- Jet #212529 ΔE 0.053
- Navy Blue #001146 ΔE 0.061
- Space Cadet #2B2D42 ΔE 0.069
- Marine #042E60 ΔE 0.074
- Gunmetal #293241 ΔE 0.076
Use #00233B 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.