#3F77D2
Closest named color: Windows Blue (#3778BF). oklch(57.8% 0.152 259.7), rgb(63, 119, 210).
Aa
Black text reads best on this color (4.78:1).
About this color
#3F77D2 is a medium-dark, vivid blue. In OKLCH its lightness is 58%, its chroma 0.152 and its hue 260°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.031 away. Black text reads best on it, at 4.78:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | vivid (0.152) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.78:1 |
| White text | 4.39:1 |
Values
| HEX | #3F77D2 |
| RGB | rgb(63, 119, 210) |
| HSL | hsl(217, 62%, 54%) |
| OKLCH | oklch(57.8% 0.152 259.7) |
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 #3F77D2 | 4.39:1 | AA large text | Lc -75.6 | Fine for body text |
| Black text on #3F77D2 | 4.78:1 | AA | Lc 34.0 | Non-text elements, placeholder text |
| #3F77D2 text on white | 4.39:1 | AA large text | Lc 70.1 | Content text, not long reading |
| #3F77D2 text on black | 4.78:1 | AA | Lc -31.5 | 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
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E2EAF8
oklch(93.5% 0.021 261.8)
-
Step 200
200
#CBDAF3
oklch(88.5% 0.038 260.7)
-
Step 300
300
#A7C2ED
oklch(80.9% 0.068 259.6)
-
Step 400
400
#77A1E5
oklch(70.6% 0.11 259.7)
-
Step 500
500
#5488DD
oklch(63% 0.14 259.8)
-
Step 600
600 (this color)
#3F77D2
oklch(57.8% 0.152 259.7)
-
Step 700
700
#2B5EAF
oklch(49.2% 0.14 259.4)
-
Step 800
800
#254D8E
oklch(42.8% 0.117 259.7)
-
Step 900
900
#234171
oklch(37.8% 0.09 259.4)
-
Step 950
950
#152642
oklch(27% 0.057 259.9)
#3F77D2 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) | #4B80D6 | 0.029 |
| Deuteranopia (no green cones) | #3072D0 | 0.020 |
| Tritanopia (no blue cones) | #008C9A | 0.121 |
| Achromatopsia (no color) | #787878 | 0.152 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F77D2
#3F77D2
oklch(57.8% 0.152 259.7)
- #9E7000
#9E7000
oklch(57.7% 0.12 80)
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 #3F77D2, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.031
- Royal Blue #4169E1 ΔE 0.045
- Water Blue #0E87CC ΔE 0.049
- Cerulean Blue #056EEE ΔE 0.059
- Cool Blue #4984B8 ΔE 0.061
- French Blue #436BAD ΔE 0.061
- Steel Blue #4682B4 ΔE 0.062
- Mid Blue #276AB3 ΔE 0.062
Use #3F77D2 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.