#303B84
Closest named color: Cobalt (#1E488F). oklch(38.6% 0.122 272.9), rgb(48, 59, 132).
Aa
White text reads best on this color (10.07:1).
About this color
#303B84 is a dark, moderately saturated blue. In OKLCH its lightness is 39%, its chroma 0.122 and its hue 273°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.039 away. White text reads best on it, at 10.07:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | moderately saturated (0.122) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.08:1 |
| White text | 10.07:1 |
Values
| HEX | #303B84 |
| RGB | rgb(48, 59, 132) |
| HSL | hsl(232, 47%, 35%) |
| OKLCH | oklch(38.6% 0.122 272.9) |
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 #303B84 | 10.07:1 | AAA | Lc -97.2 | Preferred for body text |
| Black text on #303B84 | 2.08:1 | Fails | Lc 10.8 | Not readable |
| #303B84 text on white | 10.07:1 | AAA | Lc 93.1 | Preferred for body text |
| #303B84 text on black | 2.08:1 | Fails | Lc -9.4 | 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
#CDD8FC
oklch(88.5% 0.051 271.9)
-
Step 300
300
#ADBDFC
oklch(80.9% 0.091 273.2)
-
Step 400
400
#8398FB
oklch(70.6% 0.147 273.1)
-
Step 500
500
#667BF9
oklch(63.1% 0.188 272.8)
-
Step 600
600
#5060E8
oklch(55.6% 0.204 272.7)
-
Step 700
700
#424EC9
oklch(49% 0.189 273)
-
Step 800
800
#3641A3
oklch(42.7% 0.157 272.9)
-
Step 900
900 (this color)
#303B84
oklch(38.6% 0.122 272.9)
-
Step 950
950
#1B224C
oklch(27.1% 0.078 273)
#303B84 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) | #0B4687 | 0.039 |
| Deuteranopia (no green cones) | #003E82 | 0.039 |
| Tritanopia (no blue cones) | #004C59 | 0.105 |
| Achromatopsia (no color) | #424242 | 0.122 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #303B84
#303B84
oklch(38.6% 0.122 272.9)
- #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 #303B84, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.039
- Dark Slate Blue #483D8B ΔE 0.040
- Twilight Blue #0A437A ΔE 0.043
- Blueberry #464196 ΔE 0.048
- Light Navy #155084 ΔE 0.061
- Marine Blue #01386A ΔE 0.065
- Dusk Blue #26538D ΔE 0.066
- Sapphire #2138AB ΔE 0.067
Use #303B84 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.