#303B75
Closest named color: Twilight Blue (#0A437A). oklch(37.5% 0.099 272.7), rgb(48, 59, 117).
Aa
White text reads best on this color (10.45:1).
About this color
#303B75 is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.099 and its hue 273°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.037 away. White text reads best on it, at 10.45:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.099) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.00:1 |
| White text | 10.45:1 |
Values
| HEX | #303B75 |
| RGB | rgb(48, 59, 117) |
| HSL | hsl(230, 42%, 32%) |
| OKLCH | oklch(37.5% 0.099 272.7) |
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 #303B75 | 10.45:1 | AAA | Lc -98.1 | Preferred for body text |
| Black text on #303B75 | 2.00:1 | Fails | Lc 9.8 | Not readable |
| #303B75 text on white | 10.45:1 | AAA | Lc 94.1 | Preferred for body text |
| #303B75 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
#CFD8F5
oklch(88.4% 0.041 271.9)
-
Step 300
300
#B0BEF2
oklch(80.9% 0.075 272.9)
-
Step 400
400
#889BEB
oklch(70.7% 0.119 272.8)
-
Step 500
500
#6B80E5
oklch(63.1% 0.153 272.5)
-
Step 600
600
#5567D3
oklch(55.6% 0.166 272.7)
-
Step 700
700
#4555B7
oklch(49.1% 0.155 272.4)
-
Step 800
800
#394694
oklch(42.7% 0.128 272.7)
-
Step 900
900 (this color)
#303B75
oklch(37.5% 0.099 272.7)
-
Step 950
950
#1C2345
oklch(26.9% 0.064 272.7)
#303B75 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) | #204377 | 0.027 |
| Deuteranopia (no green cones) | #163D74 | 0.029 |
| Tritanopia (no blue cones) | #064852 | 0.089 |
| Achromatopsia (no color) | #3F3F3F | 0.100 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #303B75
#303B75
oklch(37.5% 0.099 272.7)
- #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 #303B75, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.037
- Marine Blue #01386A ΔE 0.050
- Cobalt #1E488F ΔE 0.054
- Dark Slate Blue #483D8B ΔE 0.054
- Prussian Blue #1D3557 ΔE 0.061
- Dark Grey Blue #29465B ΔE 0.063
- Light Navy #155084 ΔE 0.063
- Blueberry #464196 ΔE 0.067
Use #303B75 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.