#3F7BC3
Closest named color: Windows Blue (#3778BF). oklch(57.7% 0.128 254.4), rgb(63, 123, 195).
Aa
Black text reads best on this color (4.83:1).
About this color
#3F7BC3 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 58%, its chroma 0.128 and its hue 254°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.013 away. Black text reads best on it, at 4.83:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | moderately saturated (0.128) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.83:1 |
| White text | 4.34:1 |
Values
| HEX | #3F7BC3 |
| RGB | rgb(63, 123, 195) |
| HSL | hsl(213, 52%, 51%) |
| OKLCH | oklch(57.7% 0.128 254.4) |
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 #3F7BC3 | 4.34:1 | AA large text | Lc -75.3 | Fine for body text |
| Black text on #3F7BC3 | 4.83:1 | AA | Lc 34.3 | Non-text elements, placeholder text |
| #3F7BC3 text on white | 4.34:1 | AA large text | Lc 69.8 | Content text, not long reading |
| #3F7BC3 text on black | 4.83:1 | AA | Lc -31.8 | Non-text elements, placeholder text |
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
#CBDBEE
oklch(88.5% 0.031 252.7)
-
Step 300
300
#A8C3E6
oklch(80.9% 0.058 255)
-
Step 400
400
#78A4D9
oklch(70.8% 0.092 253.6)
-
Step 500
500
#558CCF
oklch(63.2% 0.117 254.3)
-
Step 600
600 (this color)
#3F7BC3
oklch(57.7% 0.128 254.4)
-
Step 700
700
#2B62A2
oklch(49.2% 0.118 254.1)
-
Step 800
800
#255083
oklch(42.7% 0.098 254.3)
-
Step 900
900
#234369
oklch(37.8% 0.076 253.9)
-
Step 950
950
#15273E
oklch(27% 0.049 255.2)
#3F7BC3 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) | #5B80C6 | 0.034 |
| Deuteranopia (no green cones) | #4873C2 | 0.022 |
| Tritanopia (no blue cones) | #008C96 | 0.101 |
| Achromatopsia (no color) | #797979 | 0.128 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F7BC3
#3F7BC3
oklch(57.7% 0.128 254.4)
- #A36D00
#A36D00
oklch(57.7% 0.122 74.8)
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 #3F7BC3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.013
- Steel Blue #4682B4 ΔE 0.035
- Cool Blue #4984B8 ΔE 0.036
- Water Blue #0E87CC ΔE 0.037
- Nice Blue #107AB0 ΔE 0.042
- Flat Blue #3C73A8 ΔE 0.045
- French Blue #436BAD ΔE 0.051
- Off Blue #5684AE ΔE 0.052
Use #3F7BC3 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.