#042139
Closest named color: Rich Black (#0D1B2A). oklch(24.1% 0.057 247.4), rgb(4, 33, 57).
Aa
White text reads best on this color (16.38:1).
About this color
#042139 is a very dark, muted blue. In OKLCH its lightness is 24%, its chroma 0.057 and its hue 247°. Its hue sits on the cool side of the wheel. The nearest named color is Rich Black (#0D1B2A), ΔE 0.032 away. White text reads best on it, at 16.38:1.
| Hue family | Blues |
| Lightness | very dark (24%) |
| Chroma | muted (0.057) |
| Temperature | cool |
| Nearest name | Rich Black (#0D1B2A) |
| Black text | 1.28:1 |
| White text | 16.38:1 |
Values
| HEX | #042139 |
| RGB | rgb(4, 33, 57) |
| HSL | hsl(207, 87%, 12%) |
| OKLCH | oklch(24.1% 0.057 247.4) |
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 #042139 | 16.38:1 | AAA | Lc -105.6 | Preferred for body text |
| Black text on #042139 | 1.28:1 | Fails | Lc 0.0 | Not readable |
| #042139 text on white | 16.38:1 | AAA | Lc 103.1 | Preferred for body text |
| #042139 text on black | 1.28:1 | 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
#E0EBF7
oklch(93.5% 0.02 250.4)
-
Step 200
200
#C6DCF1
oklch(88.5% 0.037 247)
-
Step 300
300
#9EC5EB
oklch(80.8% 0.068 248)
-
Step 400
400
#66A6E1
oklch(70.6% 0.109 247.7)
-
Step 500
500
#368FD8
oklch(63.1% 0.138 247.2)
-
Step 600
600
#0077C4
oklch(55.5% 0.148 247.6)
-
Step 700
700
#0064A6
oklch(49.1% 0.131 247.6)
-
Step 800
800
#005289
oklch(42.7% 0.113 247.3)
-
Step 900
900
#0E446F
oklch(37.7% 0.091 247.9)
-
Step 950
950 (this color)
#042139
oklch(24.1% 0.057 247.4)
#042139 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) | #16223A | 0.021 |
| Deuteranopia (no green cones) | #0E1D39 | 0.016 |
| Tritanopia (no blue cones) | #00272A | 0.041 |
| Achromatopsia (no color) | #202020 | 0.057 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #042139
#042139
oklch(24.1% 0.057 247.4)
- #301A00
#301A00
oklch(24.2% 0.053 67.9)
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 #042139, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rich Black #0D1B2A ΔE 0.032
- Oxford Blue #1B263B ΔE 0.035
- Dark #1B2431 ΔE 0.035
- Jet #212529 ΔE 0.052
- Navy Blue #001146 ΔE 0.058
- Space Cadet #2B2D42 ΔE 0.072
- Rich Navy #001219 ΔE 0.079
- Marine #042E60 ΔE 0.079
Use #042139 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.