#04243F
Closest named color: Oxford Blue (#1B263B). oklch(25.4% 0.063 248.3), rgb(4, 36, 63).
Aa
White text reads best on this color (15.79:1).
About this color
#04243F is a dark, muted blue. In OKLCH its lightness is 25%, its chroma 0.063 and its hue 248°. Its hue sits on the cool side of the wheel. The nearest named color is Oxford Blue (#1B263B), ΔE 0.029 away. White text reads best on it, at 15.79:1.
| Hue family | Blues |
| Lightness | dark (25%) |
| Chroma | muted (0.063) |
| Temperature | cool |
| Nearest name | Oxford Blue (#1B263B) |
| Black text | 1.32:1 |
| White text | 15.79:1 |
Values
| HEX | #04243F |
| RGB | rgb(4, 36, 63) |
| HSL | hsl(207, 88%, 13%) |
| OKLCH | oklch(25.4% 0.063 248.3) |
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 #04243F | 15.79:1 | AAA | Lc -105.2 | Preferred for body text |
| Black text on #04243F | 1.32:1 | Fails | Lc 0.0 | Not readable |
| #04243F text on white | 15.79:1 | AAA | Lc 102.5 | Preferred for body text |
| #04243F text on black | 1.32:1 | 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
#DFEBF8
oklch(93.5% 0.022 250.2)
-
Step 200
200
#C5DCF4
oklch(88.5% 0.041 249.4)
-
Step 300
300
#9BC5EF
oklch(80.8% 0.075 248.8)
-
Step 400
400
#61A6E7
oklch(70.7% 0.119 248.5)
-
Step 500
500
#2A8EE0
oklch(63.1% 0.152 248.3)
-
Step 600
600
#0077C6
oklch(55.6% 0.15 248.2)
-
Step 700
700
#0064A8
oklch(49.2% 0.133 248.3)
-
Step 800
800
#00518B
oklch(42.6% 0.117 248.8)
-
Step 900
900
#054473
oklch(37.8% 0.099 248.2)
-
Step 950
950 (this color)
#04243F
oklch(25.4% 0.063 248.3)
#04243F 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) | #172640 | 0.022 |
| Deuteranopia (no green cones) | #0E203E | 0.015 |
| Tritanopia (no blue cones) | #002B2E | 0.046 |
| Achromatopsia (no color) | #232323 | 0.063 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #04243F
#04243F
oklch(25.4% 0.063 248.3)
- #341D00
#341D00
oklch(25.6% 0.056 68.8)
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 #04243F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Oxford Blue #1B263B ΔE 0.029
- Dark #1B2431 ΔE 0.036
- Rich Black #0D1B2A ΔE 0.045
- Jet #212529 ΔE 0.054
- Navy Blue #001146 ΔE 0.062
- Space Cadet #2B2D42 ΔE 0.063
- Marine #042E60 ΔE 0.065
- Gunmetal #293241 ΔE 0.070
Use #04243F 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.