#333D8F
Closest named color: Dark Slate Blue (#483D8B). oklch(40.1% 0.135 273.4), rgb(51, 61, 143).
Aa
White text reads best on this color (9.52:1).
About this color
#333D8F is a dark, moderately saturated blue. In OKLCH its lightness is 40%, its chroma 0.135 and its hue 273°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.033 away. White text reads best on it, at 9.52:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | moderately saturated (0.135) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.20:1 |
| White text | 9.52:1 |
Values
| HEX | #333D8F |
| RGB | rgb(51, 61, 143) |
| HSL | hsl(233, 47%, 38%) |
| OKLCH | oklch(40.1% 0.135 273.4) |
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 #333D8F | 9.52:1 | AAA | Lc -96.0 | Preferred for body text |
| Black text on #333D8F | 2.20:1 | Fails | Lc 12.3 | Not readable |
| #333D8F text on white | 9.52:1 | AAA | Lc 91.7 | Preferred for body text |
| #333D8F text on black | 2.20:1 | Fails | Lc -10.7 | 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
#F2F5FF
oklch(97.1% 0.014 272.7)
-
Step 100
100
#E3E9FE
oklch(93.6% 0.029 273.1)
-
Step 200
200
#CDD7FF
oklch(88.4% 0.056 274.2)
-
Step 300
300
#ACBDFF
oklch(80.9% 0.095 273)
-
Step 400
400
#8397FF
oklch(70.7% 0.153 273.6)
-
Step 500
500
#6679FF
oklch(63.1% 0.198 273.3)
-
Step 600
600
#505BF3
oklch(55.6% 0.224 273.4)
-
Step 700
700
#4249D4
oklch(49.1% 0.209 273.5)
-
Step 800
800
#363DAB
oklch(42.7% 0.173 273.6)
-
Step 900
900 (this color)
#333D8F
oklch(40.1% 0.135 273.4)
-
Step 950
950
#1A214F
oklch(27.1% 0.084 273)
#333D8F 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) | #004A92 | 0.046 |
| Deuteranopia (no green cones) | #00428D | 0.041 |
| Tritanopia (no blue cones) | #005160 | 0.114 |
| Achromatopsia (no color) | #454545 | 0.135 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #333D8F
#333D8F
oklch(40.1% 0.135 273.4)
- #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 #333D8F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.033
- Blueberry #464196 ΔE 0.034
- Cobalt #1E488F ΔE 0.034
- Sapphire #2138AB ΔE 0.052
- Twilight Blue #0A437A ΔE 0.055
- Dusk Blue #26538D ΔE 0.061
- Light Navy #155084 ΔE 0.061
- Twilight #4E518B ΔE 0.073
Use #333D8F 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.