#303F80
Closest named color: Cobalt (#1E488F). oklch(39.2% 0.111 270.8), rgb(48, 63, 128).
Aa
White text reads best on this color (9.77:1).
About this color
#303F80 is a dark, moderately saturated blue. In OKLCH its lightness is 39%, its chroma 0.111 and its hue 271°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.035 away. White text reads best on it, at 9.77:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | moderately saturated (0.111) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.14:1 |
| White text | 9.77:1 |
Values
| HEX | #303F80 |
| RGB | rgb(48, 63, 128) |
| HSL | hsl(229, 45%, 35%) |
| OKLCH | oklch(39.2% 0.111 270.8) |
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 #303F80 | 9.77:1 | AAA | Lc -96.6 | Preferred for body text |
| Black text on #303F80 | 2.14:1 | Fails | Lc 11.5 | Not readable |
| #303F80 text on white | 9.77:1 | AAA | Lc 92.4 | Preferred for body text |
| #303F80 text on black | 2.14:1 | Fails | Lc -10.0 | 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 900.
-
Step 50
50
#F2F5FD
oklch(97% 0.011 269.6)
-
Step 100
100
#E4E9FB
oklch(93.6% 0.025 273.5)
-
Step 200
200
#CDD8F9
oklch(88.4% 0.047 270.8)
-
Step 300
300
#ACBEF7
oklch(80.8% 0.083 270.9)
-
Step 400
400
#829BF3
oklch(70.7% 0.132 270.7)
-
Step 500
500
#647FEF
oklch(63.1% 0.17 270.7)
-
Step 600
600
#4D65DD
oklch(55.5% 0.184 270.7)
-
Step 700
700
#3F53C0
oklch(49.1% 0.172 270.9)
-
Step 800
800
#34459B
oklch(42.7% 0.141 270.8)
-
Step 900
900 (this color)
#303F80
oklch(39.2% 0.111 270.8)
-
Step 950
950
#1A2348
oklch(27% 0.07 270.8)
#303F80 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) | #1D4782 | 0.027 |
| Deuteranopia (no green cones) | #0E407F | 0.032 |
| Tritanopia (no blue cones) | #004E59 | 0.096 |
| Achromatopsia (no color) | #444444 | 0.111 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #303F80
#303F80
oklch(39.2% 0.111 270.8)
- #564300
#564300
oklch(39.2% 0.08 90.3)
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 #303F80, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.035
- Twilight Blue #0A437A ΔE 0.036
- Dark Slate Blue #483D8B ΔE 0.041
- Blueberry #464196 ΔE 0.050
- Light Navy #155084 ΔE 0.050
- Dusk Blue #26538D ΔE 0.057
- Marine Blue #01386A ΔE 0.063
- Deep Sea Blue #015482 ΔE 0.064
Use #303F80 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.