#333F88
Closest named color: Cobalt (#1E488F). oklch(40% 0.122 272.7), rgb(51, 63, 136).
Aa
White text reads best on this color (9.51:1).
About this color
#333F88 is a dark, moderately saturated blue. In OKLCH its lightness is 40%, 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 0.031 away. White text reads best on it, at 9.51:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | moderately saturated (0.122) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.20:1 |
| White text | 9.51:1 |
Values
| HEX | #333F88 |
| RGB | rgb(51, 63, 136) |
| HSL | hsl(232, 45%, 37%) |
| OKLCH | oklch(40% 0.122 272.7) |
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 #333F88 | 9.51:1 | AAA | Lc -96.0 | Preferred for body text |
| Black text on #333F88 | 2.20:1 | Fails | Lc 12.2 | Not readable |
| #333F88 text on white | 9.51:1 | AAA | Lc 91.7 | Preferred for body text |
| #333F88 text on black | 2.20:1 | Fails | Lc -10.6 | 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
#ACBDFC
oklch(80.8% 0.091 272.6)
-
Step 400
400
#8298FB
oklch(70.6% 0.147 272.7)
-
Step 500
500
#667BF8
oklch(63% 0.186 272.7)
-
Step 600
600
#5060E7
oklch(55.5% 0.203 272.8)
-
Step 700
700
#414EC9
oklch(49% 0.189 272.6)
-
Step 800
800
#3541A3
oklch(42.7% 0.157 272.5)
-
Step 900
900 (this color)
#333F88
oklch(40% 0.122 272.7)
-
Step 950
950
#1A224B
oklch(27% 0.076 272.1)
#333F88 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) | #14498B | 0.036 |
| Deuteranopia (no green cones) | #004286 | 0.041 |
| Tritanopia (no blue cones) | #00505D | 0.105 |
| Achromatopsia (no color) | #454545 | 0.122 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #333F88
#333F88
oklch(40% 0.122 272.7)
- #574600
#574600
oklch(40% 0.082 93)
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 #333F88, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.031
- Dark Slate Blue #483D8B ΔE 0.032
- Blueberry #464196 ΔE 0.038
- Twilight Blue #0A437A ΔE 0.046
- Light Navy #155084 ΔE 0.053
- Dusk Blue #26538D ΔE 0.055
- Sapphire #2138AB ΔE 0.064
- Deep Sea Blue #015482 ΔE 0.067
Use #333F88 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.