#40378E
Closest named color: Dark Slate Blue (#483D8B). oklch(39.9% 0.139 282.8), rgb(64, 55, 142).
Aa
White text reads best on this color (9.74:1).
About this color
#40378E is a dark, moderately saturated purple. In OKLCH its lightness is 40%, its chroma 0.139 and its hue 283°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.022 away. White text reads best on it, at 9.74:1.
| Hue family | Purples |
| Lightness | dark (40%) |
| Chroma | moderately saturated (0.139) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.15:1 |
| White text | 9.74:1 |
Values
| HEX | #40378E |
| RGB | rgb(64, 55, 142) |
| HSL | hsl(246, 44%, 39%) |
| OKLCH | oklch(39.9% 0.139 282.8) |
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 #40378E | 9.74:1 | AAA | Lc -96.5 | Preferred for body text |
| Black text on #40378E | 2.15:1 | Fails | Lc 11.7 | Not readable |
| #40378E text on white | 9.74:1 | AAA | Lc 92.2 | Preferred for body text |
| #40378E text on black | 2.15:1 | Fails | Lc -10.2 | 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
#F4F4FF
oklch(97% 0.015 286.1)
-
Step 100
100
#E6E8FE
oklch(93.6% 0.03 281.7)
-
Step 200
200
#D3D5FF
oklch(88.5% 0.058 283)
-
Step 300
300
#B7B9FF
oklch(80.9% 0.098 282.7)
-
Step 400
400
#9491FF
oklch(70.7% 0.158 282.8)
-
Step 500
500
#7D70FF
oklch(63.1% 0.205 282.9)
-
Step 600
600
#6950F3
oklch(55.6% 0.231 282.9)
-
Step 700
700
#583FD3
oklch(49.1% 0.214 282.8)
-
Step 800
800
#4735AB
oklch(42.6% 0.179 282.7)
-
Step 900
900 (this color)
#40378E
oklch(39.9% 0.139 282.8)
-
Step 950
950
#221E4F
oklch(27.1% 0.087 282.6)
#40378E 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) | #004791 | 0.065 |
| Deuteranopia (no green cones) | #00418C | 0.063 |
| Tritanopia (no blue cones) | #1E4C5D | 0.118 |
| Achromatopsia (no color) | #444444 | 0.139 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #40378E
#40378E
oklch(39.9% 0.139 282.8)
- #504900
#504900
oklch(40% 0.084 103.2)
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 #40378E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.022
- Blueberry #464196 ΔE 0.030
- Cobalt #1E488F ΔE 0.055
- Sapphire #2138AB ΔE 0.062
- Rebecca Purple #663399 ΔE 0.071
- Twilight Blue #0A437A ΔE 0.073
- Imperial Purple #480CA8 ΔE 0.075
- Twilight #4E518B ΔE 0.076
Use #40378E 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.