#3F4B8A
Closest named color: Twilight (#4E518B). oklch(43.5% 0.104 273.2), rgb(63, 75, 138).
Aa
White text reads best on this color (8.12:1).
About this color
#3F4B8A is a dark, moderately saturated blue. In OKLCH its lightness is 43%, its chroma 0.104 and its hue 273°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight (#4E518B), ΔE 0.029 away. White text reads best on it, at 8.12:1.
| Hue family | Blues |
| Lightness | dark (43%) |
| Chroma | moderately saturated (0.104) |
| Temperature | cool |
| Nearest name | Twilight (#4E518B) |
| Black text | 2.58:1 |
| White text | 8.12:1 |
Values
| HEX | #3F4B8A |
| RGB | rgb(63, 75, 138) |
| HSL | hsl(230, 37%, 39%) |
| OKLCH | oklch(43.5% 0.104 273.2) |
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 #3F4B8A | 8.12:1 | AAA | Lc -92.6 | Preferred for body text |
| Black text on #3F4B8A | 2.58:1 | Fails | Lc 16.0 | Dividers and decoration only |
| #3F4B8A text on white | 8.12:1 | AAA | Lc 88.0 | Fine for body text |
| #3F4B8A text on black | 2.58:1 | Fails | Lc -14.2 | 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
#F3F5FB
oklch(97% 0.008 271.3)
-
Step 100
100
#E6E9F6
oklch(93.6% 0.018 275.6)
-
Step 200
200
#D1D8F0
oklch(88.4% 0.034 272.8)
-
Step 300
300
#B3BFE9
oklch(81% 0.061 272.5)
-
Step 400
400
#8D9CDE
oklch(70.7% 0.098 273.8)
-
Step 500
500
#7183D5
oklch(63.2% 0.125 273)
-
Step 600
600
#5A6BC2
oklch(55.6% 0.136 272.9)
-
Step 700
700
#4A59A7
oklch(49.1% 0.125 272.8)
-
Step 800
800 (this color)
#3F4B8A
oklch(43.5% 0.104 273.2)
-
Step 900
900
#343D6C
oklch(37.6% 0.081 273.7)
-
Step 950
950
#1E2440
oklch(27% 0.053 273.2)
#3F4B8A 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) | #30538C | 0.027 |
| Deuteranopia (no green cones) | #284D89 | 0.027 |
| Tritanopia (no blue cones) | #1C5964 | 0.093 |
| Achromatopsia (no color) | #505050 | 0.105 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F4B8A
#3F4B8A
oklch(43.5% 0.104 273.2)
- #624F00
#624F00
oklch(43.4% 0.089 92.8)
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 #3F4B8A, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight #4E518B ΔE 0.029
- Dusk Blue #26538D ΔE 0.033
- Blueberry #464196 ΔE 0.036
- Dark Slate Blue #483D8B ΔE 0.039
- Cobalt #1E488F ΔE 0.040
- Dusk #4E5481 ΔE 0.041
- Light Navy #155084 ΔE 0.044
- Denim Blue #3B5B92 ΔE 0.045
Use #3F4B8A 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.