#3F74BC
Closest named color: Windows Blue (#3778BF). oklch(55.7% 0.126 256.6), rgb(63, 116, 188).
Aa
White text reads best on this color (4.73:1).
About this color
#3F74BC is a medium-dark, moderately saturated blue. In OKLCH its lightness is 56%, its chroma 0.126 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.012 away. White text reads best on it, at 4.73:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | moderately saturated (0.126) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.43:1 |
| White text | 4.73:1 |
Values
| HEX | #3F74BC |
| RGB | rgb(63, 116, 188) |
| HSL | hsl(215, 50%, 49%) |
| OKLCH | oklch(55.7% 0.126 256.6) |
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 #3F74BC | 4.73:1 | AA | Lc -78.1 | Fine for body text |
| Black text on #3F74BC | 4.43:1 | AA large text | Lc 31.5 | Non-text elements, placeholder text |
| #3F74BC text on white | 4.73:1 | AA | Lc 72.6 | Content text, not long reading |
| #3F74BC text on black | 4.43:1 | AA large text | Lc -29.1 | 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
#E3EBF5
oklch(93.7% 0.016 253.9)
-
Step 200
200
#CCDAEE
oklch(88.4% 0.031 257.2)
-
Step 300
300
#A9C3E6
oklch(81% 0.057 255.9)
-
Step 400
400
#7CA3D9
oklch(70.8% 0.09 256.6)
-
Step 500
500
#5A8BCF
oklch(63.2% 0.116 256.8)
-
Step 600
600 (this color)
#3F74BC
oklch(55.7% 0.126 256.6)
-
Step 700
700
#3161A2
oklch(49.2% 0.117 256.7)
-
Step 800
800
#294F83
oklch(42.7% 0.097 256.8)
-
Step 900
900
#264269
oklch(37.7% 0.075 256.9)
-
Step 950
950
#16273E
oklch(27% 0.049 256.3)
#3F74BC 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) | #547ABF | 0.030 |
| Deuteranopia (no green cones) | #426EBB | 0.016 |
| Tritanopia (no blue cones) | #00858F | 0.102 |
| Achromatopsia (no color) | #737373 | 0.126 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F74BC
#3F74BC
oklch(55.7% 0.126 256.6)
- #9A6900
#9A6900
oklch(55.8% 0.117 76.7)
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 #3F74BC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.012
- French Blue #436BAD ΔE 0.031
- Flat Blue #3C73A8 ΔE 0.032
- Nice Blue #107AB0 ΔE 0.038
- Mid Blue #276AB3 ΔE 0.039
- Muted Blue #3B719F ΔE 0.046
- Steel Blue #4682B4 ΔE 0.046
- Cool Blue #4984B8 ΔE 0.050
Use #3F74BC 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.