#333F8B
Closest named color: Cobalt (#1E488F). oklch(40.2% 0.126 272.7), rgb(51, 63, 139).
Aa
White text reads best on this color (9.43:1).
About this color
#333F8B is a dark, moderately saturated blue. In OKLCH its lightness is 40%, its chroma 0.126 and its hue 273°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.030 away. White text reads best on it, at 9.43:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | moderately saturated (0.126) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.22:1 |
| White text | 9.43:1 |
Values
| HEX | #333F8B |
| RGB | rgb(51, 63, 139) |
| HSL | hsl(232, 46%, 37%) |
| OKLCH | oklch(40.2% 0.126 272.7) |
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 #333F8B | 9.43:1 | AAA | Lc -95.8 | Preferred for body text |
| Black text on #333F8B | 2.22:1 | Fails | Lc 12.4 | Not readable |
| #333F8B text on white | 9.43:1 | AAA | Lc 91.5 | Preferred for body text |
| #333F8B text on black | 2.22:1 | Fails | Lc -10.8 | 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
#E3E9FD
oklch(93.5% 0.028 272.5)
-
Step 200
200
#CDD8FD
oklch(88.6% 0.052 272.2)
-
Step 300
300
#ACBDFE
oklch(80.9% 0.094 272.8)
-
Step 400
400
#8298FE
oklch(70.7% 0.151 272.8)
-
Step 500
500
#657AFC
oklch(63.1% 0.193 272.7)
-
Step 600
600
#4F5FEB
oklch(55.6% 0.209 272.6)
-
Step 700
700
#414DCD
oklch(49.2% 0.196 272.7)
-
Step 800
800
#3540A6
oklch(42.7% 0.163 272.7)
-
Step 900
900 (this color)
#333F8B
oklch(40.2% 0.126 272.7)
-
Step 950
950
#1A214D
oklch(26.9% 0.081 272.9)
#333F8B 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) | #0E4A8E | 0.040 |
| Deuteranopia (no green cones) | #004289 | 0.040 |
| Tritanopia (no blue cones) | #00515E | 0.109 |
| Achromatopsia (no color) | #464646 | 0.126 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #333F8B
#333F8B
oklch(40.2% 0.126 272.7)
- #584600
#584600
oklch(40.2% 0.082 92)
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 #333F8B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.030
- Dark Slate Blue #483D8B ΔE 0.032
- Blueberry #464196 ΔE 0.035
- Twilight Blue #0A437A ΔE 0.049
- Light Navy #155084 ΔE 0.055
- Dusk Blue #26538D ΔE 0.055
- Sapphire #2138AB ΔE 0.060
- Twilight #4E518B ΔE 0.068
Use #333F8B 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.