#40337B
Closest named color: Dark Slate Blue (#483D8B). oklch(37.6% 0.118 287.7), rgb(64, 51, 123).
Aa
White text reads best on this color (10.61:1).
About this color
#40337B is a dark, moderately saturated purple. In OKLCH its lightness is 38%, its chroma 0.118 and its hue 288°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.039 away. White text reads best on it, at 10.61:1.
| Hue family | Purples |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.118) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 1.97:1 |
| White text | 10.61:1 |
Values
| HEX | #40337B |
| RGB | rgb(64, 51, 123) |
| HSL | hsl(251, 41%, 34%) |
| OKLCH | oklch(37.6% 0.118 287.7) |
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 #40337B | 10.61:1 | AAA | Lc -98.3 | Preferred for body text |
| Black text on #40337B | 1.97:1 | Fails | Lc 9.6 | Not readable |
| #40337B text on white | 10.61:1 | AAA | Lc 94.4 | Preferred for body text |
| #40337B text on black | 1.97:1 | Fails | Lc -8.2 | 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
#F5F4FD
oklch(97% 0.012 291.3)
-
Step 100
100
#E8E8FB
oklch(93.7% 0.026 285.9)
-
Step 200
200
#D7D5F9
oklch(88.6% 0.049 287.9)
-
Step 300
300
#BDB8F7
oklch(80.9% 0.088 287.9)
-
Step 400
400
#9D91F3
oklch(70.8% 0.141 287.9)
-
Step 500
500
#8672EE
oklch(63% 0.18 287.5)
-
Step 600
600
#7256DD
oklch(55.5% 0.197 287.8)
-
Step 700
700
#6045C0
oklch(49.1% 0.183 287.8)
-
Step 800
800
#4E3A9B
oklch(42.7% 0.151 287.7)
-
Step 900
900 (this color)
#40337B
oklch(37.6% 0.118 287.7)
-
Step 950
950
#251F48
oklch(27% 0.074 287.1)
#40337B 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) | #07407D | 0.066 |
| Deuteranopia (no green cones) | #073D79 | 0.065 |
| Tritanopia (no blue cones) | #2D4351 | 0.099 |
| Achromatopsia (no color) | #3E3E3E | 0.118 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #40337B
#40337B
oklch(37.6% 0.118 287.7)
- #464400
#464400
oklch(37.6% 0.081 107.8)
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 #40337B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.039
- Blueberry #464196 ΔE 0.057
- Twilight Blue #0A437A ΔE 0.068
- Cobalt #1E488F ΔE 0.070
- Marine Blue #01386A ΔE 0.077
- Indigo #4B0082 ΔE 0.080
- Prussian Blue #1D3557 ΔE 0.084
- Rebecca Purple #663399 ΔE 0.086
Use #40337B 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.