#151B31
Closest named color: Rich Black (#0D1B2A). oklch(22.8% 0.044 271.1), rgb(21, 27, 49).
Aa
White text reads best on this color (17.03:1).
About this color
#151B31 is a very dark, muted blue. In OKLCH its lightness is 23%, its chroma 0.044 and its hue 271°. Its hue sits on the cool side of the wheel. The nearest named color is Rich Black (#0D1B2A), ΔE 0.019 away. White text reads best on it, at 17.03:1.
| Hue family | Blues |
| Lightness | very dark (23%) |
| Chroma | muted (0.044) |
| Temperature | cool |
| Nearest name | Rich Black (#0D1B2A) |
| Black text | 1.23:1 |
| White text | 17.03:1 |
Values
| HEX | #151B31 |
| RGB | rgb(21, 27, 49) |
| HSL | hsl(227, 40%, 14%) |
| OKLCH | oklch(22.8% 0.044 271.1) |
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 #151B31 | 17.03:1 | AAA | Lc -106.2 | Preferred for body text |
| Black text on #151B31 | 1.23:1 | Fails | Lc 0.0 | Not readable |
| #151B31 text on white | 17.03:1 | AAA | Lc 103.9 | Preferred for body text |
| #151B31 text on black | 1.23:1 | 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
#F4F5FA
oklch(97.1% 0.007 277.2)
-
Step 100
100
#E6EAF4
oklch(93.7% 0.014 268.5)
-
Step 200
200
#D2D9ED
oklch(88.6% 0.029 270.4)
-
Step 300
300
#B4BFE3
oklch(80.8% 0.052 271.8)
-
Step 400
400
#8D9ED5
oklch(70.7% 0.083 270.9)
-
Step 500
500
#7285CA
oklch(63.1% 0.107 271.4)
-
Step 600
600
#5B6EB6
oklch(55.6% 0.114 271.1)
-
Step 700
700
#4B5C9D
oklch(49.2% 0.106 271)
-
Step 800
800
#3D4B7F
oklch(42.6% 0.088 270.9)
-
Step 900
900
#343F66
oklch(37.7% 0.069 270.9)
-
Step 950
950 (this color)
#151B31
oklch(22.8% 0.044 271.1)
#151B31 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) | #131D32 | 0.007 |
| Deuteranopia (no green cones) | #101B31 | 0.008 |
| Tritanopia (no blue cones) | #0A2023 | 0.040 |
| Achromatopsia (no color) | #1C1C1C | 0.044 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #151B31
#151B31
oklch(22.8% 0.044 271.1)
- #241B02
#241B02
oklch(22.7% 0.043 89.9)
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 #151B31, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rich Black #0D1B2A ΔE 0.019
- Dark #1B2431 ΔE 0.034
- Oxford Blue #1B263B ΔE 0.041
- Jet #212529 ΔE 0.049
- Navy Blue #001146 ΔE 0.062
- Rich Navy #001219 ΔE 0.068
- Space Cadet #2B2D42 ΔE 0.077
- Midnight Purple #280137 ΔE 0.077
Use #151B31 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.