#042039
Closest named color: Rich Black (#0D1B2A). oklch(23.8% 0.059 249), rgb(4, 32, 57).
Aa
White text reads best on this color (16.52:1).
About this color
#042039 is a very dark, muted blue. In OKLCH its lightness is 24%, its chroma 0.059 and its hue 249°. Its hue sits on the cool side of the wheel. The nearest named color is Rich Black (#0D1B2A), ΔE 0.031 away. White text reads best on it, at 16.52:1.
| Hue family | Blues |
| Lightness | very dark (24%) |
| Chroma | muted (0.059) |
| Temperature | cool |
| Nearest name | Rich Black (#0D1B2A) |
| Black text | 1.27:1 |
| White text | 16.52:1 |
Values
| HEX | #042039 |
| RGB | rgb(4, 32, 57) |
| HSL | hsl(208, 87%, 12%) |
| OKLCH | oklch(23.8% 0.059 249) |
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 #042039 | 16.52:1 | AAA | Lc -105.8 | Preferred for body text |
| Black text on #042039 | 1.27:1 | Fails | Lc 0.0 | Not readable |
| #042039 text on white | 16.52:1 | AAA | Lc 103.2 | Preferred for body text |
| #042039 text on black | 1.27:1 | 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
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E0EBF7
oklch(93.5% 0.02 250.4)
-
Step 200
200
#C6DCF2
oklch(88.5% 0.038 248.3)
-
Step 300
300
#9EC5EC
oklch(80.9% 0.069 248.7)
-
Step 400
400
#67A6E3
oklch(70.8% 0.111 248.9)
-
Step 500
500
#388EDB
oklch(63.1% 0.142 249.1)
-
Step 600
600
#0076C8
oklch(55.5% 0.154 249.2)
-
Step 700
700
#0063A9
oklch(49% 0.136 249.1)
-
Step 800
800
#00518C
oklch(42.7% 0.118 249.2)
-
Step 900
900
#0F4470
oklch(37.8% 0.092 248.7)
-
Step 950
950 (this color)
#042039
oklch(23.8% 0.059 249)
#042039 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) | #14213A | 0.019 |
| Deuteranopia (no green cones) | #0C1D39 | 0.012 |
| Tritanopia (no blue cones) | #002629 | 0.043 |
| Achromatopsia (no color) | #1F1F1F | 0.059 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #042039
#042039
oklch(23.8% 0.059 249)
- #2E1900
#2E1900
oklch(23.7% 0.052 68.5)
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 #042039, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rich Black #0D1B2A ΔE 0.031
- Oxford Blue #1B263B ΔE 0.037
- Dark #1B2431 ΔE 0.037
- Jet #212529 ΔE 0.055
- Navy Blue #001146 ΔE 0.055
- Space Cadet #2B2D42 ΔE 0.074
- Rich Navy #001219 ΔE 0.077
- Marine #042E60 ΔE 0.081
Use #042039 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.