#42387B
Closest named color: Dark Slate Blue (#483D8B). oklch(38.8% 0.11 287), rgb(66, 56, 123).
Aa
White text reads best on this color (10.08:1).
About this color
#42387B is a dark, moderately saturated purple. In OKLCH its lightness is 39%, its chroma 0.110 and its hue 287°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.031 away. White text reads best on it, at 10.08:1.
| Hue family | Purples |
| Lightness | dark (39%) |
| Chroma | moderately saturated (0.110) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.08:1 |
| White text | 10.08:1 |
Values
| HEX | #42387B |
| RGB | rgb(66, 56, 123) |
| HSL | hsl(249, 37%, 35%) |
| OKLCH | oklch(38.8% 0.11 287) |
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 #42387B | 10.08:1 | AAA | Lc -97.3 | Preferred for body text |
| Black text on #42387B | 2.08:1 | Fails | Lc 10.7 | Not readable |
| #42387B text on white | 10.08:1 | AAA | Lc 93.2 | Preferred for body text |
| #42387B text on black | 2.08:1 | 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
#F5F4FD
oklch(97% 0.012 291.3)
-
Step 100
100
#E8E8F9
oklch(93.6% 0.023 286)
-
Step 200
200
#D6D5F7
oklch(88.4% 0.047 286.8)
-
Step 300
300
#BCB9F4
oklch(80.9% 0.083 286.7)
-
Step 400
400
#9C93EE
oklch(70.8% 0.131 287.1)
-
Step 500
500
#8575E8
oklch(63.1% 0.167 287)
-
Step 600
600
#705AD6
oklch(55.5% 0.183 287)
-
Step 700
700
#5E49BA
oklch(49.1% 0.17 286.9)
-
Step 800
800
#4D3D96
oklch(42.7% 0.14 287.2)
-
Step 900
900 (this color)
#42387B
oklch(38.8% 0.11 287)
-
Step 950
950
#252046
oklch(27.1% 0.069 286.9)
#42387B 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) | #18447D | 0.057 |
| Deuteranopia (no green cones) | #18407A | 0.055 |
| Tritanopia (no blue cones) | #304654 | 0.091 |
| Achromatopsia (no color) | #424242 | 0.110 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #42387B
#42387B
oklch(38.8% 0.11 287)
- #4A4700
#4A4700
oklch(38.8% 0.083 106.9)
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 #42387B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.031
- Blueberry #464196 ΔE 0.049
- Cobalt #1E488F ΔE 0.063
- Twilight Blue #0A437A ΔE 0.064
- Twilight #4E518B ΔE 0.075
- Light Navy #155084 ΔE 0.077
- Dusk Blue #26538D ΔE 0.079
- Marine Blue #01386A ΔE 0.080
Use #42387B 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.