#303B67
Closest named color: Prussian Blue (#1D3557). oklch(36.5% 0.077 271.5), rgb(48, 59, 103).
Aa
White text reads best on this color (10.78:1).
About this color
#303B67 is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.077 and its hue 272°. Its hue sits on the cool side of the wheel. The nearest named color is Prussian Blue (#1D3557), ΔE 0.043 away. White text reads best on it, at 10.78:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.077) |
| Temperature | cool |
| Nearest name | Prussian Blue (#1D3557) |
| Black text | 1.94:1 |
| White text | 10.78:1 |
Values
| HEX | #303B67 |
| RGB | rgb(48, 59, 103) |
| HSL | hsl(228, 36%, 30%) |
| OKLCH | oklch(36.5% 0.077 271.5) |
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 #303B67 | 10.78:1 | AAA | Lc -98.8 | Preferred for body text |
| Black text on #303B67 | 1.94:1 | Fails | Lc 9.0 | Not readable |
| #303B67 text on white | 10.78:1 | AAA | Lc 94.9 | Preferred for body text |
| #303B67 text on black | 1.94:1 | Fails | Lc -7.7 | 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
#F3F5FB
oklch(97% 0.008 271.3)
-
Step 100
100
#E6E9F5
oklch(93.5% 0.016 274.8)
-
Step 200
200
#D1D8EF
oklch(88.4% 0.033 272.2)
-
Step 300
300
#B3BFE7
oklch(80.9% 0.058 272)
-
Step 400
400
#8C9DDB
oklch(70.7% 0.093 272.1)
-
Step 500
500
#7084D1
oklch(63.1% 0.118 271.6)
-
Step 600
600
#596CBE
oklch(55.5% 0.129 271.8)
-
Step 700
700
#495AA4
oklch(49.1% 0.12 271.6)
-
Step 800
800
#3C4A85
oklch(42.7% 0.099 271.6)
-
Step 900
900 (this color)
#303B67
oklch(36.5% 0.077 271.5)
-
Step 950
950
#1E253E
oklch(27.1% 0.048 271.1)
#303B67 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) | #2A4069 | 0.016 |
| Deuteranopia (no green cones) | #243B66 | 0.016 |
| Tritanopia (no blue cones) | #19444C | 0.068 |
| Achromatopsia (no color) | #3D3D3D | 0.077 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #303B67
#303B67
oklch(36.5% 0.077 271.5)
- #4D3C00
#4D3C00
oklch(36.4% 0.074 90.7)
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 #303B67, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Prussian Blue #1D3557 ΔE 0.043
- Dark Grey Blue #29465B ΔE 0.045
- Twilight Blue #0A437A ΔE 0.046
- Marine Blue #01386A ΔE 0.046
- Dark Blue Grey #1F3B4D ΔE 0.053
- Charcoal #264653 ΔE 0.057
- Midnight Green #073B4C ΔE 0.066
- Marine #042E60 ΔE 0.067
Use #303B67 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.