#303F90
Closest named color: Cobalt (#1E488F). oklch(40.4% 0.134 271.2), rgb(48, 63, 144).
Aa
White text reads best on this color (9.37:1).
About this color
#303F90 is a dark, moderately saturated blue. In OKLCH its lightness is 40%, its chroma 0.134 and its hue 271°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.028 away. White text reads best on it, at 9.37:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | moderately saturated (0.134) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.23:1 |
| White text | 9.37:1 |
Values
| HEX | #303F90 |
| RGB | rgb(48, 63, 144) |
| HSL | hsl(231, 50%, 38%) |
| OKLCH | oklch(40.4% 0.134 271.2) |
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 #303F90 | 9.37:1 | AAA | Lc -95.6 | Preferred for body text |
| Black text on #303F90 | 2.23:1 | Fails | Lc 12.6 | Not readable |
| #303F90 text on white | 9.37:1 | AAA | Lc 91.3 | Preferred for body text |
| #303F90 text on black | 2.23:1 | Fails | Lc -11.0 | 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 800.
-
Step 50
50
#F3F5FD
oklch(97.1% 0.011 274.9)
-
Step 100
100
#E4E9FA
oklch(93.5% 0.024 272.8)
-
Step 200
200
#CED8F7
oklch(88.4% 0.044 271.3)
-
Step 300
300
#AEBEF4
oklch(80.8% 0.079 271.7)
-
Step 400
400
#849BEF
oklch(70.7% 0.126 271.3)
-
Step 500
500
#6780EA
oklch(63.2% 0.161 271.2)
-
Step 600
600
#5067D8
oklch(55.7% 0.174 271)
-
Step 700
700
#4154BB
oklch(49% 0.163 271.2)
-
Step 800
800 (this color)
#303F90
oklch(40.4% 0.134 271.2)
-
Step 900
900
#2E3B78
oklch(37.6% 0.105 271.5)
-
Step 950
950
#1B2347
oklch(27% 0.068 271.8)
#303F90 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) | #004B93 | 0.042 |
| Deuteranopia (no green cones) | #00428E | 0.036 |
| Tritanopia (no blue cones) | #005261 | 0.111 |
| Achromatopsia (no color) | #464646 | 0.135 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #303F90
#303F90
oklch(40.4% 0.134 271.2)
- #594600
#594600
oklch(40.3% 0.082 91)
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 #303F90, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.028
- Blueberry #464196 ΔE 0.035
- Dark Slate Blue #483D8B ΔE 0.036
- Sapphire #2138AB ΔE 0.051
- Twilight Blue #0A437A ΔE 0.052
- Dusk Blue #26538D ΔE 0.056
- Light Navy #155084 ΔE 0.056
- Deep Sea Blue #015482 ΔE 0.070
Use #303F90 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.