#313B74
Closest named color: Twilight Blue (#0A437A). oklch(37.5% 0.098 273.3), rgb(49, 59, 116).
Aa
White text reads best on this color (10.45:1).
About this color
#313B74 is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.098 and its hue 273°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.039 away. White text reads best on it, at 10.45:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.098) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.00:1 |
| White text | 10.45:1 |
Values
| HEX | #313B74 |
| RGB | rgb(49, 59, 116) |
| HSL | hsl(231, 41%, 32%) |
| OKLCH | oklch(37.5% 0.098 273.3) |
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 #313B74 | 10.45:1 | AAA | Lc -98.1 | Preferred for body text |
| Black text on #313B74 | 2.00:1 | Fails | Lc 9.8 | Not readable |
| #313B74 text on white | 10.45:1 | AAA | Lc 94.1 | Preferred for body text |
| #313B74 text on black | 2.00:1 | Fails | Lc -8.5 | 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
#F3F5FC
oklch(97.1% 0.01 273.4)
-
Step 100
100
#E5E9F9
oklch(93.6% 0.022 274.7)
-
Step 200
200
#D0D8F5
oklch(88.5% 0.041 273.3)
-
Step 300
300
#B1BEF1
oklch(80.9% 0.074 273.5)
-
Step 400
400
#899BEA
oklch(70.8% 0.118 273.3)
-
Step 500
500
#6D80E3
oklch(63.1% 0.15 273.2)
-
Step 600
600
#5767D1
oklch(55.6% 0.163 273.5)
-
Step 700
700
#4755B5
oklch(49.1% 0.152 273.3)
-
Step 800
800
#3A4692
oklch(42.6% 0.125 273.2)
-
Step 900
900 (this color)
#313B74
oklch(37.5% 0.098 273.3)
-
Step 950
950
#1D2344
oklch(26.9% 0.062 273.8)
#313B74 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) | #214276 | 0.025 |
| Deuteranopia (no green cones) | #183D73 | 0.028 |
| Tritanopia (no blue cones) | #0D4852 | 0.087 |
| Achromatopsia (no color) | #3F3F3F | 0.098 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #313B74
#313B74
oklch(37.5% 0.098 273.3)
- #4F3F00
#4F3F00
oklch(37.4% 0.077 92.6)
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 #313B74, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.039
- Marine Blue #01386A ΔE 0.051
- Dark Slate Blue #483D8B ΔE 0.054
- Cobalt #1E488F ΔE 0.055
- Prussian Blue #1D3557 ΔE 0.060
- Dark Grey Blue #29465B ΔE 0.061
- Light Navy #155084 ΔE 0.063
- Blueberry #464196 ΔE 0.068
Use #313B74 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.