#303166
Closest named color: Prussian Blue (#1D3557). oklch(34.2% 0.091 279.6), rgb(48, 49, 102).
Aa
White text reads best on this color (11.95:1).
About this color
#303166 is a dark, moderately saturated blue. In OKLCH its lightness is 34%, its chroma 0.091 and its hue 280°. Its hue sits on the cool side of the wheel. The nearest named color is Prussian Blue (#1D3557), ΔE 0.041 away. White text reads best on it, at 11.95:1.
| Hue family | Blues |
| Lightness | dark (34%) |
| Chroma | moderately saturated (0.091) |
| Temperature | cool |
| Nearest name | Prussian Blue (#1D3557) |
| Black text | 1.75:1 |
| White text | 11.95:1 |
Values
| HEX | #303166 |
| RGB | rgb(48, 49, 102) |
| HSL | hsl(239, 36%, 29%) |
| OKLCH | oklch(34.2% 0.091 279.6) |
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 #303166 | 11.95:1 | AAA | Lc -100.8 | Preferred for body text |
| Black text on #303166 | 1.75:1 | Fails | Lc 0.0 | Not readable |
| #303166 text on white | 11.95:1 | AAA | Lc 97.2 | Preferred for body text |
| #303166 text on black | 1.75:1 | Fails | Lc 0.0 | 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
#F4F5FC
oklch(97.1% 0.009 279.7)
-
Step 100
100
#E7E9F7
oklch(93.7% 0.019 279.5)
-
Step 200
200
#D3D7F2
oklch(88.4% 0.037 278.9)
-
Step 300
300
#B7BDED
oklch(81% 0.068 279.2)
-
Step 400
400
#9399E4
oklch(70.8% 0.109 279.7)
-
Step 500
500
#7A7EDB
oklch(63.1% 0.138 279.8)
-
Step 600
600
#6465C9
oklch(55.6% 0.151 279.8)
-
Step 700
700
#5353AE
oklch(49.1% 0.142 279.8)
-
Step 800
800
#44458D
oklch(42.8% 0.116 279.7)
-
Step 900
900 (this color)
#303166
oklch(34.2% 0.091 279.6)
-
Step 950
950
#212342
oklch(27.1% 0.057 279.1)
#303166 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) | #193968 | 0.034 |
| Deuteranopia (no green cones) | #143565 | 0.035 |
| Tritanopia (no blue cones) | #1B3C46 | 0.079 |
| Achromatopsia (no color) | #373737 | 0.091 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #303166
#303166
oklch(34.2% 0.091 279.6)
- #413900
#413900
oklch(34.2% 0.071 100.6)
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 #303166, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Prussian Blue #1D3557 ΔE 0.041
- Marine Blue #01386A ΔE 0.047
- Marine #042E60 ΔE 0.053
- Twilight Blue #0A437A ΔE 0.063
- Dark Blue Grey #1F3B4D ΔE 0.064
- Space Cadet #2B2D42 ΔE 0.065
- Gunmetal #293241 ΔE 0.069
- Dark Grey Blue #29465B ΔE 0.072
Use #303166 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.