#3F509B
Closest named color: Twilight (#4E518B). oklch(45.7% 0.123 271.2), rgb(63, 80, 155).
Aa
White text reads best on this color (7.41:1).
About this color
#3F509B is a medium-dark, moderately saturated blue. In OKLCH its lightness is 46%, its chroma 0.123 and its hue 271°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight (#4E518B), ΔE 0.034 away. White text reads best on it, at 7.41:1.
| Hue family | Blues |
| Lightness | medium-dark (46%) |
| Chroma | moderately saturated (0.123) |
| Temperature | cool |
| Nearest name | Twilight (#4E518B) |
| Black text | 2.83:1 |
| White text | 7.41:1 |
Values
| HEX | #3F509B |
| RGB | rgb(63, 80, 155) |
| HSL | hsl(229, 42%, 43%) |
| OKLCH | oklch(45.7% 0.123 271.2) |
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 #3F509B | 7.41:1 | AAA | Lc -90.4 | Preferred for body text |
| Black text on #3F509B | 2.83:1 | Fails | Lc 18.5 | Dividers and decoration only |
| #3F509B text on white | 7.41:1 | AAA | Lc 85.5 | Fine for body text |
| #3F509B text on black | 2.83:1 | Fails | Lc -16.5 | 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
#F3F5FC
oklch(97.1% 0.01 273.4)
-
Step 100
100
#E4E9F8
oklch(93.5% 0.021 271.2)
-
Step 200
200
#CFD8F4
oklch(88.4% 0.04 271.4)
-
Step 300
300
#AFBFF0
oklch(80.9% 0.072 270.6)
-
Step 400
400
#869CE9
oklch(70.7% 0.116 271.1)
-
Step 500
500
#6A81E2
oklch(63.1% 0.148 271.5)
-
Step 600
600
#5369D0
oklch(55.7% 0.16 271.3)
-
Step 700
700
#4357B4
oklch(49.2% 0.149 270.9)
-
Step 800
800 (this color)
#3F509B
oklch(45.7% 0.123 271.2)
-
Step 900
900
#2F3D74
oklch(37.8% 0.095 270.5)
-
Step 950
950
#1C2444
oklch(27.1% 0.06 271.3)
#3F509B 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) | #2C5A9E | 0.031 |
| Deuteranopia (no green cones) | #1D5299 | 0.034 |
| Tritanopia (no blue cones) | #00616E | 0.109 |
| Achromatopsia (no color) | #555555 | 0.123 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F509B
#3F509B
oklch(45.7% 0.123 271.2)
- #6B5400
#6B5400
oklch(45.7% 0.093 90.3)
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 #3F509B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight #4E518B ΔE 0.034
- Denim Blue #3B5B92 ΔE 0.037
- Dusk Blue #26538D ΔE 0.038
- Blueberry #464196 ΔE 0.039
- Dusky Blue #475F94 ΔE 0.048
- Light Navy Blue #2E5A88 ΔE 0.049
- Cobalt #1E488F ΔE 0.049
- Dusk #4E5481 ΔE 0.051
Use #3F509B 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.