#333591
Closest named color: Dark Slate Blue (#483D8B). oklch(38.7% 0.148 276), rgb(51, 53, 145).
Aa
White text reads best on this color (10.19:1).
About this color
#333591 is a dark, vivid blue. In OKLCH its lightness is 39%, its chroma 0.148 and its hue 276°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.043 away. White text reads best on it, at 10.19:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | vivid (0.148) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.05:1 |
| White text | 10.19:1 |
Values
| HEX | #333591 |
| RGB | rgb(51, 53, 145) |
| HSL | hsl(239, 48%, 38%) |
| OKLCH | oklch(38.7% 0.148 276) |
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 #333591 | 10.19:1 | AAA | Lc -97.3 | Preferred for body text |
| Black text on #333591 | 2.05:1 | Fails | Lc 10.7 | Not readable |
| #333591 text on white | 10.19:1 | AAA | Lc 93.2 | Preferred for body text |
| #333591 text on black | 2.05:1 | Fails | Lc -9.3 | 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
#F3F5FF
oklch(97.2% 0.013 277.1)
-
Step 100
100
#E4E9FF
oklch(93.7% 0.03 275.6)
-
Step 200
200
#CED7FF
oklch(88.5% 0.056 275.2)
-
Step 300
300
#AFBCFF
oklch(80.9% 0.096 275.6)
-
Step 400
400
#8896FF
oklch(70.8% 0.153 276)
-
Step 500
500
#6D76FF
oklch(63% 0.2 276.2)
-
Step 600
600
#5752FF
oklch(55.7% 0.247 276.1)
-
Step 700
700
#4840DE
oklch(49.1% 0.229 276)
-
Step 800
800
#3A37B3
oklch(42.7% 0.189 275.9)
-
Step 900
900 (this color)
#333591
oklch(38.7% 0.148 276)
-
Step 950
950
#1C1E53
oklch(26.9% 0.095 276.3)
#333591 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) | #004594 | 0.051 |
| Deuteranopia (no green cones) | #003D8F | 0.044 |
| Tritanopia (no blue cones) | #004C5E | 0.123 |
| Achromatopsia (no color) | #414141 | 0.149 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #333591
#333591
oklch(38.7% 0.148 276)
- #514300
#514300
oklch(38.6% 0.079 95.5)
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 #333591, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.043
- Blueberry #464196 ΔE 0.045
- Sapphire #2138AB ΔE 0.048
- Cobalt #1E488F ΔE 0.051
- Twilight Blue #0A437A ΔE 0.065
- Indigo Blue #3A18B1 ΔE 0.067
- Imperial Purple #480CA8 ΔE 0.073
- Light Navy #155084 ΔE 0.080
Use #333591 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.