#303C83
Closest named color: Cobalt (#1E488F). oklch(38.7% 0.119 272.4), rgb(48, 60, 131).
Aa
White text reads best on this color (10.00:1).
About this color
#303C83 is a dark, moderately saturated blue. In OKLCH its lightness is 39%, its chroma 0.119 and its hue 272°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.038 away. White text reads best on it, at 10.00:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | moderately saturated (0.119) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.09:1 |
| White text | 10.00:1 |
Values
| HEX | #303C83 |
| RGB | rgb(48, 60, 131) |
| HSL | hsl(231, 46%, 35%) |
| OKLCH | oklch(38.7% 0.119 272.4) |
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 #303C83 | 10.00:1 | AAA | Lc -97.1 | Preferred for body text |
| Black text on #303C83 | 2.09:1 | Fails | Lc 11.0 | Not readable |
| #303C83 text on white | 10.00:1 | AAA | Lc 92.9 | Preferred for body text |
| #303C83 text on black | 2.09:1 | Fails | Lc -9.5 | 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
#F2F5FE
oklch(97% 0.012 271.3)
-
Step 100
100
#E4E9FC
oklch(93.6% 0.026 274.1)
-
Step 200
200
#CDD8FB
oklch(88.5% 0.05 271.6)
-
Step 300
300
#ADBDFB
oklch(80.8% 0.09 273.1)
-
Step 400
400
#8399F9
oklch(70.7% 0.143 272.5)
-
Step 500
500
#667CF6
oklch(63.1% 0.183 272.4)
-
Step 600
600
#5061E5
oklch(55.5% 0.199 272.6)
-
Step 700
700
#414FC7
oklch(49% 0.185 272.5)
-
Step 800
800
#3542A1
oklch(42.7% 0.153 272.3)
-
Step 900
900 (this color)
#303C83
oklch(38.7% 0.119 272.4)
-
Step 950
950
#1A224B
oklch(27% 0.076 272.1)
#303C83 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) | #114686 | 0.036 |
| Deuteranopia (no green cones) | #003F82 | 0.038 |
| Tritanopia (no blue cones) | #004D59 | 0.104 |
| Achromatopsia (no color) | #424242 | 0.120 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #303C83
#303C83
oklch(38.7% 0.119 272.4)
- #534200
#534200
oklch(38.6% 0.079 92.2)
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 #303C83, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.038
- Dark Slate Blue #483D8B ΔE 0.040
- Twilight Blue #0A437A ΔE 0.041
- Blueberry #464196 ΔE 0.048
- Light Navy #155084 ΔE 0.058
- Marine Blue #01386A ΔE 0.064
- Dusk Blue #26538D ΔE 0.064
- Sapphire #2138AB ΔE 0.069
Use #303C83 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.