#3F429C
Closest named color: Blueberry (#464196). oklch(43% 0.144 277.1), rgb(63, 66, 156).
Aa
White text reads best on this color (8.49:1).
About this color
#3F429C is a dark, vivid blue. In OKLCH its lightness is 43%, its chroma 0.144 and its hue 277°. Its hue sits on the cool side of the wheel. The nearest named color is Blueberry (#464196), ΔE 0.014 away. White text reads best on it, at 8.49:1.
| Hue family | Blues |
| Lightness | dark (43%) |
| Chroma | vivid (0.144) |
| Temperature | cool |
| Nearest name | Blueberry (#464196) |
| Black text | 2.47:1 |
| White text | 8.49:1 |
Values
| HEX | #3F429C |
| RGB | rgb(63, 66, 156) |
| HSL | hsl(238, 42%, 43%) |
| OKLCH | oklch(43% 0.144 277.1) |
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 #3F429C | 8.49:1 | AAA | Lc -93.5 | Preferred for body text |
| Black text on #3F429C | 2.47:1 | Fails | Lc 15.1 | Dividers and decoration only |
| #3F429C text on white | 8.49:1 | AAA | Lc 88.9 | Fine for body text |
| #3F429C text on black | 2.47:1 | Fails | Lc -13.3 | 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 800.
-
Step 50
50
#F3F5FD
oklch(97.1% 0.011 274.9)
-
Step 100
100
#E5E9FB
oklch(93.6% 0.025 275.9)
-
Step 200
200
#D1D7F9
oklch(88.5% 0.047 277.5)
-
Step 300
300
#B2BCF7
oklch(80.8% 0.084 276.9)
-
Step 400
400
#8C97F3
oklch(70.6% 0.135 277.2)
-
Step 500
500
#727BEF
oklch(63.2% 0.171 277)
-
Step 600
600
#5C60DD
oklch(55.5% 0.187 277)
-
Step 700
700
#4C4FC0
oklch(49.1% 0.173 276.8)
-
Step 800
800 (this color)
#3F429C
oklch(43% 0.144 277.1)
-
Step 900
900
#34387B
oklch(37.6% 0.112 277)
-
Step 950
950
#1E2248
oklch(27% 0.07 276.2)
#3F429C 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) | #00519F | 0.057 |
| Deuteranopia (no green cones) | #00499A | 0.053 |
| Tritanopia (no blue cones) | #005768 | 0.125 |
| Achromatopsia (no color) | #4D4D4D | 0.144 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F429C
#3F429C
oklch(43% 0.144 277.1)
- #5D4F00
#5D4F00
oklch(42.9% 0.088 97.4)
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 #3F429C, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Blueberry #464196 ΔE 0.014
- Dark Slate Blue #483D8B ΔE 0.032
- Cobalt #1E488F ΔE 0.046
- Sapphire #2138AB ΔE 0.053
- Twilight #4E518B ΔE 0.059
- Dusk Blue #26538D ΔE 0.059
- Light Navy #155084 ΔE 0.070
- Rebecca Purple #663399 ΔE 0.072
Use #3F429C 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.