#3F72BC
Closest named color: Windows Blue (#3778BF). oklch(55.3% 0.128 257.8), rgb(63, 114, 188).
Aa
White text reads best on this color (4.83:1).
About this color
#3F72BC is a medium-dark, moderately saturated blue. In OKLCH its lightness is 55%, its chroma 0.128 and its hue 258°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.017 away. White text reads best on it, at 4.83:1.
| Hue family | Blues |
| Lightness | medium-dark (55%) |
| Chroma | moderately saturated (0.128) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.34:1 |
| White text | 4.83:1 |
Values
| HEX | #3F72BC |
| RGB | rgb(63, 114, 188) |
| HSL | hsl(216, 50%, 49%) |
| OKLCH | oklch(55.3% 0.128 257.8) |
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 #3F72BC | 4.83:1 | AA | Lc -78.7 | Fine for body text |
| Black text on #3F72BC | 4.34:1 | AA large text | Lc 30.8 | Non-text elements, placeholder text |
| #3F72BC text on white | 4.83:1 | AA | Lc 73.3 | Content text, not long reading |
| #3F72BC text on black | 4.34:1 | AA large text | Lc -28.4 | 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 600.
-
Step 50
50
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E3EAF5
oklch(93.5% 0.017 259.4)
-
Step 200
200
#CCDAEF
oklch(88.4% 0.033 258.4)
-
Step 300
300
#AAC2E6
oklch(80.8% 0.057 258.4)
-
Step 400
400
#7CA2DA
oklch(70.6% 0.093 257.9)
-
Step 500
500
#5B8AD0
oklch(63.1% 0.118 258.1)
-
Step 600
600 (this color)
#3F72BC
oklch(55.3% 0.128 257.8)
-
Step 700
700
#3260A3
oklch(49.1% 0.119 257.9)
-
Step 800
800
#2A4F84
oklch(42.8% 0.098 257.6)
-
Step 900
900
#26426A
oklch(37.8% 0.077 257.4)
-
Step 950
950
#17273E
oklch(27.1% 0.048 257.5)
#3F72BC 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) | #5178BF | 0.027 |
| Deuteranopia (no green cones) | #3E6CBA | 0.017 |
| Tritanopia (no blue cones) | #00838E | 0.103 |
| Achromatopsia (no color) | #727272 | 0.128 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F72BC
#3F72BC
oklch(55.3% 0.128 257.8)
- #976800
#976800
oklch(55.2% 0.115 77.6)
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 #3F72BC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.017
- French Blue #436BAD ΔE 0.027
- Flat Blue #3C73A8 ΔE 0.033
- Mid Blue #276AB3 ΔE 0.035
- Nice Blue #107AB0 ΔE 0.041
- Muted Blue #3B719F ΔE 0.046
- Steel Blue #4682B4 ΔE 0.051
- Dull Blue #49759C ΔE 0.054
Use #3F72BC 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.