#303D66
Closest named color: Dark Grey Blue (#29465B). oklch(36.9% 0.073 269.3), rgb(48, 61, 102).
Aa
White text reads best on this color (10.57:1).
About this color
#303D66 is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.073 and its hue 269°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Grey Blue (#29465B), ΔE 0.039 away. White text reads best on it, at 10.57:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.073) |
| Temperature | cool |
| Nearest name | Dark Grey Blue (#29465B) |
| Black text | 1.98:1 |
| White text | 10.57:1 |
Values
| HEX | #303D66 |
| RGB | rgb(48, 61, 102) |
| HSL | hsl(226, 36%, 29%) |
| OKLCH | oklch(36.9% 0.073 269.3) |
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 #303D66 | 10.57:1 | AAA | Lc -98.4 | Preferred for body text |
| Black text on #303D66 | 1.98:1 | Fails | Lc 9.5 | Not readable |
| #303D66 text on white | 10.57:1 | AAA | Lc 94.4 | Preferred for body text |
| #303D66 text on black | 1.98:1 | Fails | Lc -8.1 | 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
#E5EAF5
oklch(93.6% 0.016 266.3)
-
Step 200
200
#D1D9EE
oklch(88.6% 0.03 269.1)
-
Step 300
300
#B2C0E5
oklch(80.9% 0.055 268.9)
-
Step 400
400
#8A9ED8
oklch(70.6% 0.088 269.4)
-
Step 500
500
#6E86CD
oklch(63.2% 0.111 268.9)
-
Step 600
600
#576EBA
oklch(55.6% 0.121 269.5)
-
Step 700
700
#475CA0
oklch(49.1% 0.112 269.1)
-
Step 800
800
#3A4B82
oklch(42.6% 0.094 269.2)
-
Step 900
900 (this color)
#303D66
oklch(36.9% 0.073 269.3)
-
Step 950
950
#1D253D
oklch(26.9% 0.046 269.1)
#303D66 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) | #2D4168 | 0.012 |
| Deuteranopia (no green cones) | #273D65 | 0.012 |
| Tritanopia (no blue cones) | #19464C | 0.066 |
| Achromatopsia (no color) | #3F3F3F | 0.073 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #303D66
#303D66
oklch(36.9% 0.073 269.3)
- #4F3D04
#4F3D04
oklch(36.9% 0.073 89.1)
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 #303D66, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Grey Blue #29465B ΔE 0.039
- Prussian Blue #1D3557 ΔE 0.044
- Twilight Blue #0A437A ΔE 0.045
- Marine Blue #01386A ΔE 0.049
- Dark Blue Grey #1F3B4D ΔE 0.051
- Charcoal #264653 ΔE 0.051
- Midnight Green #073B4C ΔE 0.064
- Onyx #343A40 ΔE 0.065
Use #303D66 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.