#403F8E
Closest named color: Dark Slate Blue (#483D8B). oklch(41.4% 0.127 279.8), rgb(64, 63, 142).
Aa
White text reads best on this color (9.05:1).
About this color
#403F8E is a dark, moderately saturated blue. In OKLCH its lightness is 41%, its chroma 0.127 and its hue 280°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.014 away. White text reads best on it, at 9.05:1.
| Hue family | Blues |
| Lightness | dark (41%) |
| Chroma | moderately saturated (0.127) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.31:1 |
| White text | 9.05:1 |
Values
| HEX | #403F8E |
| RGB | rgb(64, 63, 142) |
| HSL | hsl(241, 39%, 40%) |
| OKLCH | oklch(41.4% 0.127 279.8) |
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 #403F8E | 9.05:1 | AAA | Lc -95.0 | Preferred for body text |
| Black text on #403F8E | 2.31:1 | Fails | Lc 13.4 | Not readable |
| #403F8E text on white | 9.05:1 | AAA | Lc 90.5 | Preferred for body text |
| #403F8E text on black | 2.31:1 | Fails | Lc -11.8 | 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 800.
-
Step 50
50
#F4F5FC
oklch(97.1% 0.009 279.7)
-
Step 100
100
#E7E9F9
oklch(93.7% 0.022 280.3)
-
Step 200
200
#D3D7F5
oklch(88.5% 0.041 279.5)
-
Step 300
300
#B6BCF1
oklch(80.9% 0.075 279.5)
-
Step 400
400
#9298E9
oklch(70.7% 0.118 279.7)
-
Step 500
500
#797CE3
oklch(63.2% 0.152 279.8)
-
Step 600
600
#6363D1
oklch(55.7% 0.165 279.6)
-
Step 700
700
#5351B5
oklch(49.2% 0.154 280)
-
Step 800
800 (this color)
#403F8E
oklch(41.4% 0.127 279.8)
-
Step 900
900
#383975
oklch(37.7% 0.1 279.7)
-
Step 950
950
#212244
oklch(27% 0.062 280.1)
#403F8E 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) | #0F4C91 | 0.055 |
| Deuteranopia (no green cones) | #00468C | 0.058 |
| Tritanopia (no blue cones) | #1D5160 | 0.110 |
| Achromatopsia (no color) | #494949 | 0.128 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #403F8E
#403F8E
oklch(41.4% 0.127 279.8)
- #574C00
#574C00
oklch(41.5% 0.086 99.8)
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 #403F8E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.014
- Blueberry #464196 ΔE 0.017
- Cobalt #1E488F ΔE 0.043
- Twilight #4E518B ΔE 0.057
- Dusk Blue #26538D ΔE 0.059
- Light Navy #155084 ΔE 0.065
- Sapphire #2138AB ΔE 0.066
- Twilight Blue #0A437A ΔE 0.067
Use #403F8E 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.