#3F458B
Closest named color: Dark Slate Blue (#483D8B). oklch(42.3% 0.115 276.6), rgb(63, 69, 139).
Aa
White text reads best on this color (8.62:1).
About this color
#3F458B is a dark, moderately saturated blue. In OKLCH its lightness is 42%, its chroma 0.115 and its hue 277°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.024 away. White text reads best on it, at 8.62:1.
| Hue family | Blues |
| Lightness | dark (42%) |
| Chroma | moderately saturated (0.115) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.43:1 |
| White text | 8.62:1 |
Values
| HEX | #3F458B |
| RGB | rgb(63, 69, 139) |
| HSL | hsl(235, 38%, 40%) |
| OKLCH | oklch(42.3% 0.115 276.6) |
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 #3F458B | 8.62:1 | AAA | Lc -93.9 | Preferred for body text |
| Black text on #3F458B | 2.43:1 | Fails | Lc 14.6 | Not readable |
| #3F458B text on white | 8.62:1 | AAA | Lc 89.4 | Fine for body text |
| #3F458B text on black | 2.43:1 | Fails | Lc -12.8 | 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
#E6E9F7
oklch(93.6% 0.019 276.3)
-
Step 200
200
#D2D8F2
oklch(88.6% 0.036 275.3)
-
Step 300
300
#B5BDEC
oklch(80.8% 0.067 277.2)
-
Step 400
400
#8F9AE3
oklch(70.6% 0.107 276.7)
-
Step 500
500
#7580DB
oklch(63.2% 0.137 276.5)
-
Step 600
600
#5F67C8
oklch(55.6% 0.148 276.9)
-
Step 700
700
#4E55AD
oklch(49% 0.138 276.6)
-
Step 800
800 (this color)
#3F458B
oklch(42.3% 0.115 276.6)
-
Step 900
900
#363C70
oklch(37.8% 0.088 276.3)
-
Step 950
950
#1F2342
oklch(26.9% 0.058 276.3)
#3F458B 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) | #244F8E | 0.038 |
| Deuteranopia (no green cones) | #1A4989 | 0.041 |
| Tritanopia (no blue cones) | #1C5461 | 0.100 |
| Achromatopsia (no color) | #4C4C4C | 0.115 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F458B
#3F458B
oklch(42.3% 0.115 276.6)
- #5C4D00
#5C4D00
oklch(42.3% 0.087 96.2)
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 #3F458B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.024
- Blueberry #464196 ΔE 0.024
- Cobalt #1E488F ΔE 0.038
- Twilight #4E518B ΔE 0.043
- Dusk Blue #26538D ΔE 0.045
- Light Navy #155084 ΔE 0.052
- Dusk #4E5481 ΔE 0.056
- Denim Blue #3B5B92 ΔE 0.061
Use #3F458B 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.