#3F439B
Closest named color: Blueberry (#464196). oklch(43.1% 0.141 276.8), rgb(63, 67, 155).
Aa
White text reads best on this color (8.44:1).
About this color
#3F439B is a dark, vivid blue. In OKLCH its lightness is 43%, its chroma 0.141 and its hue 277°. Its hue sits on the cool side of the wheel. The nearest named color is Blueberry (#464196), ΔE 0.013 away. White text reads best on it, at 8.44:1.
| Hue family | Blues |
| Lightness | dark (43%) |
| Chroma | vivid (0.141) |
| Temperature | cool |
| Nearest name | Blueberry (#464196) |
| Black text | 2.48:1 |
| White text | 8.44:1 |
Values
| HEX | #3F439B |
| RGB | rgb(63, 67, 155) |
| HSL | hsl(237, 42%, 43%) |
| OKLCH | oklch(43.1% 0.141 276.8) |
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 #3F439B | 8.44:1 | AAA | Lc -93.3 | Preferred for body text |
| Black text on #3F439B | 2.48:1 | Fails | Lc 15.2 | Dividers and decoration only |
| #3F439B text on white | 8.44:1 | AAA | Lc 88.8 | Fine for body text |
| #3F439B text on black | 2.48:1 | Fails | Lc -13.4 | 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
#F3F5FD
oklch(97.1% 0.011 274.9)
-
Step 100
100
#E5E9FA
oklch(93.6% 0.023 275.4)
-
Step 200
200
#D1D7F8
oklch(88.5% 0.046 277.3)
-
Step 300
300
#B2BCF6
oklch(80.8% 0.083 276.8)
-
Step 400
400
#8C98F2
oklch(70.8% 0.132 276.7)
-
Step 500
500
#727BED
oklch(63.1% 0.169 277)
-
Step 600
600
#5C61DB
oklch(55.5% 0.183 276.9)
-
Step 700
700
#4C50BE
oklch(49.2% 0.169 276.6)
-
Step 800
800 (this color)
#3F439B
oklch(43.1% 0.141 276.8)
-
Step 900
900
#34397A
oklch(37.7% 0.109 276.5)
-
Step 950
950
#1E2248
oklch(27% 0.07 276.2)
#3F439B 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) | #00519E | 0.056 |
| Deuteranopia (no green cones) | #004999 | 0.052 |
| Tritanopia (no blue cones) | #005868 | 0.124 |
| Achromatopsia (no color) | #4D4D4D | 0.141 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F439B
#3F439B
oklch(43.1% 0.141 276.8)
- #5E4F00
#5E4F00
oklch(43% 0.089 96.5)
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 #3F439B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Blueberry #464196 ΔE 0.013
- Dark Slate Blue #483D8B ΔE 0.031
- Cobalt #1E488F ΔE 0.044
- Sapphire #2138AB ΔE 0.056
- Twilight #4E518B ΔE 0.056
- Dusk Blue #26538D ΔE 0.056
- Light Navy #155084 ΔE 0.068
- Denim Blue #3B5B92 ΔE 0.069
Use #3F439B 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.