#3F4588
Closest named color: Dark Slate Blue (#483D8B). oklch(42.1% 0.11 276.7), rgb(63, 69, 136).
Aa
White text reads best on this color (8.68:1).
About this color
#3F4588 is a dark, moderately saturated blue. In OKLCH its lightness is 42%, its chroma 0.110 and its hue 277°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.025 away. White text reads best on it, at 8.68:1.
| Hue family | Blues |
| Lightness | dark (42%) |
| Chroma | moderately saturated (0.110) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.41:1 |
| White text | 8.68:1 |
Values
| HEX | #3F4588 |
| RGB | rgb(63, 69, 136) |
| HSL | hsl(235, 37%, 39%) |
| OKLCH | oklch(42.1% 0.11 276.7) |
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 #3F4588 | 8.68:1 | AAA | Lc -94.1 | Preferred for body text |
| Black text on #3F4588 | 2.41:1 | Fails | Lc 14.4 | Not readable |
| #3F4588 text on white | 8.68:1 | AAA | Lc 89.6 | Fine for body text |
| #3F4588 text on black | 2.41:1 | Fails | Lc -12.6 | 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
#F4F5FB
oklch(97.1% 0.008 278.6)
-
Step 100
100
#E6E9F7
oklch(93.6% 0.019 276.3)
-
Step 200
200
#D2D8F1
oklch(88.5% 0.035 274.9)
-
Step 300
300
#B5BEEB
oklch(81% 0.064 276)
-
Step 400
400
#909BE0
oklch(70.8% 0.102 276.5)
-
Step 500
500
#7680D8
oklch(63.1% 0.132 277)
-
Step 600
600
#5F68C5
oklch(55.6% 0.143 276.5)
-
Step 700
700
#4F56AA
oklch(49.1% 0.132 276.8)
-
Step 800
800 (this color)
#3F4588
oklch(42.1% 0.11 276.7)
-
Step 900
900
#363C6E
oklch(37.7% 0.085 276.3)
-
Step 950
950
#202341
oklch(27% 0.056 277.7)
#3F4588 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) | #264E8A | 0.036 |
| Deuteranopia (no green cones) | #1F4887 | 0.037 |
| Tritanopia (no blue cones) | #1F5460 | 0.097 |
| Achromatopsia (no color) | #4B4B4B | 0.110 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F4588
#3F4588
oklch(42.1% 0.11 276.7)
- #5B4D00
#5B4D00
oklch(42.2% 0.087 97.1)
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 #3F4588, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.025
- Blueberry #464196 ΔE 0.028
- Cobalt #1E488F ΔE 0.038
- Twilight #4E518B ΔE 0.043
- Dusk Blue #26538D ΔE 0.044
- Light Navy #155084 ΔE 0.050
- Dusk #4E5481 ΔE 0.054
- Twilight Blue #0A437A ΔE 0.060
Use #3F4588 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.