#303B5E
Closest named color: Prussian Blue (#1D3557). oklch(36% 0.063 269.8), rgb(48, 59, 94).
Aa
White text reads best on this color (10.97:1).
About this color
#303B5E is a dark, muted blue. In OKLCH its lightness is 36%, its chroma 0.063 and its hue 270°. Its hue sits on the cool side of the wheel. The nearest named color is Prussian Blue (#1D3557), ΔE 0.035 away. White text reads best on it, at 10.97:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | muted (0.063) |
| Temperature | cool |
| Nearest name | Prussian Blue (#1D3557) |
| Black text | 1.91:1 |
| White text | 10.97:1 |
Values
| HEX | #303B5E |
| RGB | rgb(48, 59, 94) |
| HSL | hsl(226, 32%, 28%) |
| OKLCH | oklch(36% 0.063 269.8) |
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 #303B5E | 10.97:1 | AAA | Lc -99.2 | Preferred for body text |
| Black text on #303B5E | 1.91:1 | Fails | Lc 8.6 | Not readable |
| #303B5E text on white | 10.97:1 | AAA | Lc 95.3 | Preferred for body text |
| #303B5E text on black | 1.91:1 | Fails | Lc -7.3 | 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
#F4F5FA
oklch(97.1% 0.007 277.2)
-
Step 100
100
#E6EAF3
oklch(93.7% 0.013 266.7)
-
Step 200
200
#D2D9EB
oklch(88.5% 0.026 268.8)
-
Step 300
300
#B4C0E0
oklch(80.9% 0.047 269.1)
-
Step 400
400
#8E9FD0
oklch(70.7% 0.075 269.6)
-
Step 500
500
#7286C4
oklch(63% 0.097 269.8)
-
Step 600
600
#5B6FB1
oklch(55.5% 0.106 269.9)
-
Step 700
700
#4B5D98
oklch(49.1% 0.097 269.7)
-
Step 800
800
#3E4C7B
oklch(42.7% 0.08 270.2)
-
Step 900
900 (this color)
#303B5E
oklch(36% 0.063 269.8)
-
Step 950
950
#1F253A
oklch(26.9% 0.04 271.3)
#303B5E 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) | #2E3E5F | 0.009 |
| Deuteranopia (no green cones) | #2A3A5D | 0.010 |
| Tritanopia (no blue cones) | #1F4248 | 0.055 |
| Achromatopsia (no color) | #3C3C3C | 0.063 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #303B5E
#303B5E
oklch(36% 0.063 269.8)
- #4A3B10
#4A3B10
oklch(35.9% 0.062 89.2)
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 #303B5E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Prussian Blue #1D3557 ΔE 0.035
- Dark Grey Blue #29465B ΔE 0.037
- Dark Blue Grey #1F3B4D ΔE 0.039
- Charcoal #264653 ΔE 0.046
- Marine Blue #01386A ΔE 0.050
- Onyx #343A40 ΔE 0.053
- Midnight Green #073B4C ΔE 0.055
- Gunmetal #293241 ΔE 0.056
Use #303B5E 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.