#313A66
Closest named color: Prussian Blue (#1D3557). oklch(36.3% 0.077 273.3), rgb(49, 58, 102).
Aa
White text reads best on this color (10.89:1).
About this color
#313A66 is a dark, moderately saturated blue. In OKLCH its lightness is 36%, its chroma 0.077 and its hue 273°. Its hue sits on the cool side of the wheel. The nearest named color is Prussian Blue (#1D3557), ΔE 0.042 away. White text reads best on it, at 10.89:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | moderately saturated (0.077) |
| Temperature | cool |
| Nearest name | Prussian Blue (#1D3557) |
| Black text | 1.92:1 |
| White text | 10.89:1 |
Values
| HEX | #313A66 |
| RGB | rgb(49, 58, 102) |
| HSL | hsl(230, 35%, 30%) |
| OKLCH | oklch(36.3% 0.077 273.3) |
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 #313A66 | 10.89:1 | AAA | Lc -99.0 | Preferred for body text |
| Black text on #313A66 | 1.92:1 | Fails | Lc 8.8 | Not readable |
| #313A66 text on white | 10.89:1 | AAA | Lc 95.1 | Preferred for body text |
| #313A66 text on black | 1.92:1 | Fails | Lc -7.5 | 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
#F4F5FB
oklch(97.1% 0.008 278.6)
-
Step 100
100
#E6E9F5
oklch(93.5% 0.016 274.8)
-
Step 200
200
#D2D8EF
oklch(88.5% 0.032 274.1)
-
Step 300
300
#B4BFE7
oklch(81% 0.058 273)
-
Step 400
400
#8E9DDA
oklch(70.8% 0.091 273.2)
-
Step 500
500
#7383D0
oklch(63% 0.117 273.7)
-
Step 600
600
#5C6CBE
oklch(55.7% 0.128 273.2)
-
Step 700
700
#4C59A3
oklch(49% 0.119 273.7)
-
Step 800
800
#3E4984
oklch(42.6% 0.098 273.6)
-
Step 900
900 (this color)
#313A66
oklch(36.3% 0.077 273.3)
-
Step 950
950
#1F243E
oklch(26.9% 0.049 274.4)
#313A66 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) | #293F68 | 0.017 |
| Deuteranopia (no green cones) | #243B65 | 0.018 |
| Tritanopia (no blue cones) | #1C434B | 0.067 |
| Achromatopsia (no color) | #3D3D3D | 0.077 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #313A66
#313A66
oklch(36.3% 0.077 273.3)
- #4B3C00
#4B3C00
oklch(36.2% 0.074 93)
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 #313A66, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Prussian Blue #1D3557 ΔE 0.042
- Marine Blue #01386A ΔE 0.047
- Dark Grey Blue #29465B ΔE 0.047
- Twilight Blue #0A437A ΔE 0.049
- Dark Blue Grey #1F3B4D ΔE 0.053
- Charcoal #264653 ΔE 0.058
- Marine #042E60 ΔE 0.066
- Midnight Green #073B4C ΔE 0.066
Use #313A66 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.