#303D9B
Closest named color: Sapphire (#2138AB). oklch(40.9% 0.153 271.8), rgb(48, 61, 155).
Aa
White text reads best on this color (9.26:1).
About this color
#303D9B is a dark, vivid blue. In OKLCH its lightness is 41%, its chroma 0.153 and its hue 272°. Its hue sits on the cool side of the wheel. The nearest named color is Sapphire (#2138AB), ΔE 0.034 away. White text reads best on it, at 9.26:1.
| Hue family | Blues |
| Lightness | dark (41%) |
| Chroma | vivid (0.153) |
| Temperature | cool |
| Nearest name | Sapphire (#2138AB) |
| Black text | 2.26:1 |
| White text | 9.26:1 |
Values
| HEX | #303D9B |
| RGB | rgb(48, 61, 155) |
| HSL | hsl(233, 53%, 40%) |
| OKLCH | oklch(40.9% 0.153 271.8) |
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 #303D9B | 9.26:1 | AAA | Lc -95.3 | Preferred for body text |
| Black text on #303D9B | 2.26:1 | Fails | Lc 13.1 | Not readable |
| #303D9B text on white | 9.26:1 | AAA | Lc 90.9 | Preferred for body text |
| #303D9B text on black | 2.26:1 | Fails | Lc -11.4 | 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 800.
-
Step 50
50
#F2F5FE
oklch(97% 0.012 271.3)
-
Step 100
100
#E3E9FC
oklch(93.5% 0.027 271.9)
-
Step 200
200
#CDD8FB
oklch(88.5% 0.05 271.6)
-
Step 300
300
#ACBEFB
oklch(81% 0.089 271.6)
-
Step 400
400
#8299F9
oklch(70.7% 0.143 272.1)
-
Step 500
500
#657CF6
oklch(63% 0.183 272.1)
-
Step 600
600
#4E62E5
oklch(55.6% 0.198 271.8)
-
Step 700
700
#4050C7
oklch(49.1% 0.184 271.9)
-
Step 800
800 (this color)
#303D9B
oklch(40.9% 0.153 271.8)
-
Step 900
900
#2D3980
oklch(37.7% 0.12 272.1)
-
Step 950
950
#1A224B
oklch(27% 0.076 272.1)
#303D9B 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) | #004C9E | 0.045 |
| Deuteranopia (no green cones) | #004299 | 0.036 |
| Tritanopia (no blue cones) | #005466 | 0.123 |
| Achromatopsia (no color) | #474747 | 0.153 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #303D9B
#303D9B
oklch(40.9% 0.153 271.8)
- #5B4800
#5B4800
oklch(41% 0.084 91.5)
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 #303D9B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Sapphire #2138AB ΔE 0.034
- Blueberry #464196 ΔE 0.036
- Cobalt #1E488F ΔE 0.038
- Dark Slate Blue #483D8B ΔE 0.044
- Dusk Blue #26538D ΔE 0.066
- Twilight Blue #0A437A ΔE 0.068
- Light Navy #155084 ΔE 0.069
- Indigo Blue #3A18B1 ΔE 0.070
Use #303D9B 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.