#303B90
Closest named color: Cobalt (#1E488F). oklch(39.6% 0.14 272.7), rgb(48, 59, 144).
Aa
White text reads best on this color (9.74:1).
About this color
#303B90 is a dark, moderately saturated blue. In OKLCH its lightness is 40%, its chroma 0.140 and its hue 273°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.036 away. White text reads best on it, at 9.74:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | moderately saturated (0.140) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.15:1 |
| White text | 9.74:1 |
Values
| HEX | #303B90 |
| RGB | rgb(48, 59, 144) |
| HSL | hsl(233, 50%, 38%) |
| OKLCH | oklch(39.6% 0.14 272.7) |
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 #303B90 | 9.74:1 | AAA | Lc -96.4 | Preferred for body text |
| Black text on #303B90 | 2.15:1 | Fails | Lc 11.7 | Not readable |
| #303B90 text on white | 9.74:1 | AAA | Lc 92.2 | Preferred for body text |
| #303B90 text on black | 2.15:1 | Fails | Lc -10.2 | 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
#F2F5FF
oklch(97.1% 0.014 272.7)
-
Step 100
100
#E3E9FF
oklch(93.6% 0.03 273.6)
-
Step 200
200
#CCD8FF
oklch(88.6% 0.055 271.8)
-
Step 300
300
#ACBDFF
oklch(80.9% 0.095 273)
-
Step 400
400
#8198FF
oklch(70.7% 0.153 272.5)
-
Step 500
500
#6479FF
oklch(63% 0.199 272.7)
-
Step 600
600
#4D59F8
oklch(55.6% 0.233 272.7)
-
Step 700
700
#3F47D8
oklch(49% 0.217 272.7)
-
Step 800
800
#333CAF
oklch(42.7% 0.18 272.6)
-
Step 900
900 (this color)
#303B90
oklch(39.6% 0.14 272.7)
-
Step 950
950
#192051
oklch(26.9% 0.089 272.8)
#303B90 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) | #004893 | 0.044 |
| Deuteranopia (no green cones) | #00408E | 0.038 |
| Tritanopia (no blue cones) | #00505F | 0.117 |
| Achromatopsia (no color) | #444444 | 0.140 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #303B90
#303B90
oklch(39.6% 0.14 272.7)
- #564500
#564500
oklch(39.7% 0.081 92.8)
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 #303B90, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.036
- Dark Slate Blue #483D8B ΔE 0.039
- Blueberry #464196 ΔE 0.039
- Sapphire #2138AB ΔE 0.048
- Twilight Blue #0A437A ΔE 0.055
- Light Navy #155084 ΔE 0.065
- Dusk Blue #26538D ΔE 0.066
- Indigo Blue #3A18B1 ΔE 0.078
Use #303B90 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.