#001F3B
Closest named color: Rich Black (#0D1B2A). oklch(23.5% 0.065 249.2), rgb(0, 31, 59).
Aa
White text reads best on this color (16.67:1).
About this color
#001F3B is a very dark, muted blue. In OKLCH its lightness is 23%, its chroma 0.065 and its hue 249°. Its hue sits on the cool side of the wheel. The nearest named color is Rich Black (#0D1B2A), ΔE 0.034 away. White text reads best on it, at 16.67:1.
| Hue family | Blues |
| Lightness | very dark (23%) |
| Chroma | muted (0.065) |
| Temperature | cool |
| Nearest name | Rich Black (#0D1B2A) |
| Black text | 1.25:1 |
| White text | 16.67:1 |
Values
| HEX | #001F3B |
| RGB | rgb(0, 31, 59) |
| HSL | hsl(208, 100%, 12%) |
| OKLCH | oklch(23.5% 0.065 249.2) |
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 #001F3B | 16.67:1 | AAA | Lc -105.8 | Preferred for body text |
| Black text on #001F3B | 1.25:1 | Fails | Lc 0.0 | Not readable |
| #001F3B text on white | 16.67:1 | AAA | Lc 103.3 | Preferred for body text |
| #001F3B text on black | 1.25:1 | 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
#DFEBF9
oklch(93.5% 0.023 252.2)
-
Step 200
200
#C4DCF5
oklch(88.5% 0.043 249.4)
-
Step 300
300
#9AC5F1
oklch(80.8% 0.078 249.4)
-
Step 400
400
#5FA6EA
oklch(70.7% 0.123 249)
-
Step 500
500
#278DE4
oklch(63% 0.159 249.5)
-
Step 600
600
#0076C8
oklch(55.5% 0.154 249.2)
-
Step 700
700
#0063AA
oklch(49.1% 0.137 249.4)
-
Step 800
800
#00518C
oklch(42.7% 0.118 249.2)
-
Step 900
900
#024375
oklch(37.6% 0.103 249.4)
-
Step 950
950 (this color)
#001F3B
oklch(23.5% 0.065 249.2)
#001F3B 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) | #11213C | 0.021 |
| Deuteranopia (no green cones) | #061C3A | 0.011 |
| Tritanopia (no blue cones) | #00262A | 0.047 |
| Achromatopsia (no color) | #1E1E1E | 0.065 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #001F3B
#001F3B
oklch(23.5% 0.065 249.2)
- #2D1900
#2D1900
oklch(23.5% 0.051 70.1)
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 #001F3B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rich Black #0D1B2A ΔE 0.034
- Oxford Blue #1B263B ΔE 0.043
- Dark #1B2431 ΔE 0.044
- Navy Blue #001146 ΔE 0.048
- Jet #212529 ΔE 0.062
- Night Blue #040348 ΔE 0.076
- Rich Navy #001219 ΔE 0.077
- Space Cadet #2B2D42 ΔE 0.080
Use #001F3B 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.