#3F4F8A
Closest named color: Twilight (#4E518B). oklch(44.4% 0.099 270.5), rgb(63, 79, 138).
Aa
White text reads best on this color (7.78:1).
About this color
#3F4F8A is a dark, moderately saturated blue. In OKLCH its lightness is 44%, its chroma 0.099 and its hue 271°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight (#4E518B), ΔE 0.023 away. White text reads best on it, at 7.78:1.
| Hue family | Blues |
| Lightness | dark (44%) |
| Chroma | moderately saturated (0.099) |
| Temperature | cool |
| Nearest name | Twilight (#4E518B) |
| Black text | 2.69:1 |
| White text | 7.78:1 |
Values
| HEX | #3F4F8A |
| RGB | rgb(63, 79, 138) |
| HSL | hsl(227, 37%, 39%) |
| OKLCH | oklch(44.4% 0.099 270.5) |
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 #3F4F8A | 7.78:1 | AAA | Lc -91.6 | Preferred for body text |
| Black text on #3F4F8A | 2.69:1 | Fails | Lc 17.1 | Dividers and decoration only |
| #3F4F8A text on white | 7.78:1 | AAA | Lc 86.9 | Fine for body text |
| #3F4F8A text on black | 2.69:1 | Fails | Lc -15.2 | Dividers and decoration only |
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
#E5EAF5
oklch(93.6% 0.016 266.3)
-
Step 200
200
#D1D9EF
oklch(88.6% 0.031 269.8)
-
Step 300
300
#B2BFE7
oklch(80.8% 0.058 270.9)
-
Step 400
400
#8B9EDB
oklch(70.8% 0.092 270.6)
-
Step 500
500
#6E85D1
oklch(63.2% 0.118 270)
-
Step 600
600
#576DBE
oklch(55.6% 0.128 270.4)
-
Step 700
700
#475BA4
oklch(49.2% 0.119 270)
-
Step 800
800 (this color)
#3F4F8A
oklch(44.4% 0.099 270.5)
-
Step 900
900
#323E6A
oklch(37.6% 0.077 270.8)
-
Step 950
950
#1D253E
oklch(27% 0.048 269.5)
#3F4F8A 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) | #37568C | 0.021 |
| Deuteranopia (no green cones) | #2E4F89 | 0.021 |
| Tritanopia (no blue cones) | #1B5C66 | 0.088 |
| Achromatopsia (no color) | #525252 | 0.099 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F4F8A
#3F4F8A
oklch(44.4% 0.099 270.5)
- #675100
#675100
oklch(44.5% 0.091 90.6)
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 #3F4F8A, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight #4E518B ΔE 0.023
- Dusk Blue #26538D ΔE 0.028
- Dusk #4E5481 ΔE 0.032
- Denim Blue #3B5B92 ΔE 0.034
- Light Navy Blue #2E5A88 ΔE 0.036
- Light Navy #155084 ΔE 0.043
- Blueberry #464196 ΔE 0.045
- Cobalt #1E488F ΔE 0.045
Use #3F4F8A 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.