#04243A
Closest named color: Oxford Blue (#1B263B). oklch(25% 0.055 243.3), rgb(4, 36, 58).
Aa
White text reads best on this color (15.92:1).
About this color
#04243A is a dark, muted blue. In OKLCH its lightness is 25%, its chroma 0.055 and its hue 243°. Its hue sits on the cool side of the wheel. The nearest named color is Oxford Blue (#1B263B), ΔE 0.028 away. White text reads best on it, at 15.92:1.
| Hue family | Blues |
| Lightness | dark (25%) |
| Chroma | muted (0.055) |
| Temperature | cool |
| Nearest name | Oxford Blue (#1B263B) |
| Black text | 1.31:1 |
| White text | 15.92:1 |
Values
| HEX | #04243A |
| RGB | rgb(4, 36, 58) |
| HSL | hsl(204, 87%, 12%) |
| OKLCH | oklch(25% 0.055 243.3) |
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 #04243A | 15.92:1 | AAA | Lc -105.3 | Preferred for body text |
| Black text on #04243A | 1.31:1 | Fails | Lc 0.0 | Not readable |
| #04243A text on white | 15.92:1 | AAA | Lc 102.7 | Preferred for body text |
| #04243A text on black | 1.31:1 | 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
#F1F6FB
oklch(97.1% 0.009 247.9)
-
Step 100
100
#E0ECF6
oklch(93.7% 0.019 243)
-
Step 200
200
#C5DDF0
oklch(88.6% 0.037 241.8)
-
Step 300
300
#9CC6E8
oklch(80.8% 0.066 243.1)
-
Step 400
400
#63A8DD
oklch(70.7% 0.105 243.2)
-
Step 500
500
#2E91D4
oklch(63.2% 0.134 243.3)
-
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
#005483
oklch(42.8% 0.104 243)
-
Step 900
900
#07456C
oklch(37.6% 0.088 243.8)
-
Step 950
950 (this color)
#04243A
oklch(25% 0.055 243.3)
#04243A 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) | #1A253B | 0.026 |
| Deuteranopia (no green cones) | #12203A | 0.018 |
| Tritanopia (no blue cones) | #00292C | 0.037 |
| Achromatopsia (no color) | #222222 | 0.055 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #04243A
#04243A
oklch(25% 0.055 243.3)
- #341B01
#341B01
oklch(25.1% 0.055 63.5)
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 #04243A, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Oxford Blue #1B263B ΔE 0.028
- Dark #1B2431 ΔE 0.030
- Rich Black #0D1B2A ΔE 0.039
- Jet #212529 ΔE 0.047
- Space Cadet #2B2D42 ΔE 0.064
- Navy Blue #001146 ΔE 0.067
- Gunmetal #293241 ΔE 0.071
- Marine #042E60 ΔE 0.073
Use #04243A 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.