#303B70
Closest named color: Twilight Blue (#0A437A). oklch(37.1% 0.092 272.4), rgb(48, 59, 112).
Aa
White text reads best on this color (10.57:1).
About this color
#303B70 is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.092 and its hue 272°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.039 away. White text reads best on it, at 10.57:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.092) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.98:1 |
| White text | 10.57:1 |
Values
| HEX | #303B70 |
| RGB | rgb(48, 59, 112) |
| HSL | hsl(230, 40%, 31%) |
| OKLCH | oklch(37.1% 0.092 272.4) |
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 #303B70 | 10.57:1 | AAA | Lc -98.4 | Preferred for body text |
| Black text on #303B70 | 1.98:1 | Fails | Lc 9.5 | Not readable |
| #303B70 text on white | 10.57:1 | AAA | Lc 94.4 | Preferred for body text |
| #303B70 text on black | 1.98:1 | Fails | Lc -8.2 | 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
#F3F5FC
oklch(97.1% 0.01 273.4)
-
Step 100
100
#E5E9F8
oklch(93.5% 0.021 274)
-
Step 200
200
#D0D8F3
oklch(88.5% 0.038 272.5)
-
Step 300
300
#B1BFEE
oklch(81% 0.068 271.9)
-
Step 400
400
#899CE5
oklch(70.7% 0.109 272.2)
-
Step 500
500
#6D81DE
oklch(63% 0.141 272.6)
-
Step 600
600
#5669CB
oklch(55.6% 0.152 272.3)
-
Step 700
700
#4757B0
oklch(49.1% 0.142 272.5)
-
Step 800
800
#3A488E
oklch(42.8% 0.116 272.1)
-
Step 900
900 (this color)
#303B70
oklch(37.1% 0.092 272.4)
-
Step 950
950
#1D2443
oklch(27.1% 0.058 272.4)
#303B70 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) | #244272 | 0.023 |
| Deuteranopia (no green cones) | #1C3C6F | 0.024 |
| Tritanopia (no blue cones) | #0F4750 | 0.082 |
| Achromatopsia (no color) | #3F3F3F | 0.092 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #303B70
#303B70
oklch(37.1% 0.092 272.4)
- #4E3E00
#4E3E00
oklch(37% 0.076 92.3)
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 #303B70, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.039
- Marine Blue #01386A ΔE 0.047
- Prussian Blue #1D3557 ΔE 0.054
- Dark Grey Blue #29465B ΔE 0.056
- Cobalt #1E488F ΔE 0.060
- Dark Slate Blue #483D8B ΔE 0.060
- Light Navy #155084 ΔE 0.065
- Dark Blue Grey #1F3B4D ΔE 0.067
Use #303B70 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.