#1F3181
Closest named color: Marine Blue (#01386A). oklch(35.3% 0.136 268.6), rgb(31, 49, 129).
Aa
White text reads best on this color (11.57:1).
About this color
#1F3181 is a dark, moderately saturated blue. In OKLCH its lightness is 35%, its chroma 0.136 and its hue 269°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.050 away. White text reads best on it, at 11.57:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | moderately saturated (0.136) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.81:1 |
| White text | 11.57:1 |
Values
| HEX | #1F3181 |
| RGB | rgb(31, 49, 129) |
| HSL | hsl(229, 61%, 31%) |
| OKLCH | oklch(35.3% 0.136 268.6) |
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 #1F3181 | 11.57:1 | AAA | Lc -99.9 | Preferred for body text |
| Black text on #1F3181 | 1.81:1 | Fails | Lc 7.8 | Not readable |
| #1F3181 text on white | 11.57:1 | AAA | Lc 96.1 | Preferred for body text |
| #1F3181 text on black | 1.81:1 | 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 900.
-
Step 50
50
#F1F5FF
oklch(97% 0.014 268.5)
-
Step 100
100
#E1EAFE
oklch(93.6% 0.029 266.4)
-
Step 200
200
#CAD8FF
oklch(88.4% 0.056 269.7)
-
Step 300
300
#A7BFFF
oklch(81% 0.095 268.4)
-
Step 400
400
#799AFF
oklch(70.6% 0.153 268.6)
-
Step 500
500
#597DFF
oklch(63.2% 0.197 268.6)
-
Step 600
600
#3F5FF5
oklch(55.6% 0.226 268.5)
-
Step 700
700
#324CD6
oklch(49% 0.212 268.6)
-
Step 800
800
#2940AD
oklch(42.7% 0.175 268.5)
-
Step 900
900 (this color)
#1F3181
oklch(35.3% 0.136 268.6)
-
Step 950
950
#152250
oklch(27.1% 0.086 268.3)
#1F3181 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) | #003E84 | 0.036 |
| Deuteranopia (no green cones) | #00347F | 0.023 |
| Tritanopia (no blue cones) | #004554 | 0.107 |
| Achromatopsia (no color) | #393939 | 0.137 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1F3181
#1F3181
oklch(35.3% 0.136 268.6)
- #4B3900
#4B3900
oklch(35.4% 0.072 88.8)
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 #1F3181, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.050
- Twilight Blue #0A437A ΔE 0.052
- Royal #0C1793 ΔE 0.064
- Marine #042E60 ΔE 0.064
- Cobalt #1E488F ΔE 0.065
- Midnight Blue #191970 ΔE 0.066
- Sapphire #2138AB ΔE 0.072
- Dark Slate Blue #483D8B ΔE 0.074
Use #1F3181 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.