#303B68
Closest named color: Prussian Blue (#1D3557). oklch(36.6% 0.079 271.7), rgb(48, 59, 104).
Aa
White text reads best on this color (10.76:1).
About this color
#303B68 is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.079 and its hue 272°. Its hue sits on the cool side of the wheel. The nearest named color is Prussian Blue (#1D3557), ΔE 0.044 away. White text reads best on it, at 10.76:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.079) |
| Temperature | cool |
| Nearest name | Prussian Blue (#1D3557) |
| Black text | 1.95:1 |
| White text | 10.76:1 |
Values
| HEX | #303B68 |
| RGB | rgb(48, 59, 104) |
| HSL | hsl(228, 37%, 30%) |
| OKLCH | oklch(36.6% 0.079 271.7) |
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 #303B68 | 10.76:1 | AAA | Lc -98.7 | Preferred for body text |
| Black text on #303B68 | 1.95:1 | Fails | Lc 9.1 | Not readable |
| #303B68 text on white | 10.76:1 | AAA | Lc 94.8 | Preferred for body text |
| #303B68 text on black | 1.95:1 | Fails | Lc -7.8 | 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
#E5E9F6
oklch(93.5% 0.018 272.3)
-
Step 200
200
#D1D8F0
oklch(88.4% 0.034 272.8)
-
Step 300
300
#B3BFE8
oklch(80.9% 0.06 272.2)
-
Step 400
400
#8B9DDC
oklch(70.6% 0.095 271.6)
-
Step 500
500
#7084D3
oklch(63.2% 0.121 271.8)
-
Step 600
600
#596CC0
oklch(55.7% 0.132 271.9)
-
Step 700
700
#495AA5
oklch(49.1% 0.121 271.7)
-
Step 800
800
#3C4A86
oklch(42.8% 0.101 271.7)
-
Step 900
900 (this color)
#303B68
oklch(36.6% 0.079 271.7)
-
Step 950
950
#1E253F
oklch(27.1% 0.049 271.4)
#303B68 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) | #29406A | 0.016 |
| Deuteranopia (no green cones) | #233B67 | 0.017 |
| Tritanopia (no blue cones) | #18454C | 0.071 |
| Achromatopsia (no color) | #3E3E3E | 0.079 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #303B68
#303B68
oklch(36.6% 0.079 271.7)
- #4D3D00
#4D3D00
oklch(36.7% 0.075 92.1)
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 #303B68, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Prussian Blue #1D3557 ΔE 0.044
- Twilight Blue #0A437A ΔE 0.045
- Marine Blue #01386A ΔE 0.046
- Dark Grey Blue #29465B ΔE 0.046
- Dark Blue Grey #1F3B4D ΔE 0.055
- Charcoal #264653 ΔE 0.058
- Marine #042E60 ΔE 0.067
- Midnight Green #073B4C ΔE 0.068
Use #303B68 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.