#40337E
Closest named color: Dark Slate Blue (#483D8B). oklch(37.8% 0.122 287), rgb(64, 51, 126).
Aa
White text reads best on this color (10.53:1).
About this color
#40337E is a dark, moderately saturated purple. In OKLCH its lightness is 38%, its chroma 0.122 and its hue 287°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.036 away. White text reads best on it, at 10.53:1.
| Hue family | Purples |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.122) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 1.99:1 |
| White text | 10.53:1 |
Values
| HEX | #40337E |
| RGB | rgb(64, 51, 126) |
| HSL | hsl(250, 42%, 35%) |
| OKLCH | oklch(37.8% 0.122 287) |
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 #40337E | 10.53:1 | AAA | Lc -98.2 | Preferred for body text |
| Black text on #40337E | 1.99:1 | Fails | Lc 9.8 | Not readable |
| #40337E text on white | 10.53:1 | AAA | Lc 94.2 | Preferred for body text |
| #40337E text on black | 1.99:1 | Fails | Lc -8.4 | 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
#F5F4FE
oklch(97.1% 0.013 290.8)
-
Step 100
100
#E8E8FB
oklch(93.7% 0.026 285.9)
-
Step 200
200
#D6D5FA
oklch(88.6% 0.051 286.6)
-
Step 300
300
#BCB8F9
oklch(80.9% 0.091 287)
-
Step 400
400
#9B90F6
oklch(70.6% 0.146 287)
-
Step 500
500
#8571F2
oklch(63.1% 0.186 286.9)
-
Step 600
600
#7155E1
oklch(55.6% 0.203 287)
-
Step 700
700
#5F44C3
oklch(49.1% 0.188 287.1)
-
Step 800
800
#4D399E
oklch(42.7% 0.156 286.9)
-
Step 900
900 (this color)
#40337E
oklch(37.8% 0.122 287)
-
Step 950
950
#251E4A
oklch(27% 0.079 287.2)
#40337E 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) | #004181 | 0.069 |
| Deuteranopia (no green cones) | #003D7C | 0.068 |
| Tritanopia (no blue cones) | #2B4453 | 0.102 |
| Achromatopsia (no color) | #3F3F3F | 0.122 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #40337E
#40337E
oklch(37.8% 0.122 287)
- #474400
#474400
oklch(37.7% 0.081 106.8)
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 #40337E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.036
- Blueberry #464196 ΔE 0.053
- Cobalt #1E488F ΔE 0.068
- Twilight Blue #0A437A ΔE 0.069
- Indigo #4B0082 ΔE 0.079
- Marine Blue #01386A ΔE 0.080
- Rebecca Purple #663399 ΔE 0.083
- Sapphire #2138AB ΔE 0.085
Use #40337E 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.