#3F7CDD
Closest named color: Windows Blue (#3778BF). oklch(59.5% 0.161 259.3), rgb(63, 124, 221).
Aa
Black text reads best on this color (5.13:1).
About this color
#3F7CDD is a medium-dark, vivid blue. In OKLCH its lightness is 60%, its chroma 0.161 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.047 away. Black text reads best on it, at 5.13:1.
| Hue family | Blues |
| Lightness | medium-dark (60%) |
| Chroma | vivid (0.161) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 5.13:1 |
| White text | 4.08:1 |
Values
| HEX | #3F7CDD |
| RGB | rgb(63, 124, 221) |
| HSL | hsl(217, 70%, 56%) |
| OKLCH | oklch(59.5% 0.161 259.3) |
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 #3F7CDD | 4.08:1 | AA large text | Lc -73.2 | Content text, not long reading |
| Black text on #3F7CDD | 5.13:1 | AA | Lc 36.4 | Non-text elements, placeholder text |
| #3F7CDD text on white | 4.08:1 | AA large text | Lc 67.7 | Content text, not long reading |
| #3F7CDD text on black | 5.13:1 | AA | Lc -34.0 | 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 500.
-
Step 50
50
#F1F6FD
oklch(97.1% 0.011 256.7)
-
Step 100
100
#E1EBFA
oklch(93.7% 0.023 258.4)
-
Step 200
200
#C8DAF7
oklch(88.4% 0.045 259.9)
-
Step 300
300
#A3C2F4
oklch(80.9% 0.079 259.9)
-
Step 400
400
#70A1EF
oklch(70.7% 0.127 259.4)
-
Step 500
500 (this color)
#3F7CDD
oklch(59.5% 0.161 259.3)
-
Step 600
600
#2B6ED7
oklch(55.5% 0.175 259.4)
-
Step 700
700
#1E5CBB
oklch(49.2% 0.163 259.3)
-
Step 800
800
#1B4B97
oklch(42.6% 0.135 259.5)
-
Step 900
900
#1C4078
oklch(37.7% 0.104 259.1)
-
Step 950
950
#112646
oklch(27% 0.066 258.6)
#3F7CDD 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) | #4C85E1 | 0.029 |
| Deuteranopia (no green cones) | #2E77DB | 0.020 |
| Tritanopia (no blue cones) | #0093A2 | 0.127 |
| Achromatopsia (no color) | #7E7E7E | 0.161 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F7CDD
#3F7CDD
oklch(59.5% 0.161 259.3)
- #A57500
#A57500
oklch(59.6% 0.123 79.9)
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 #3F7CDD, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.047
- Water Blue #0E87CC ΔE 0.048
- Dark Sky Blue #448EE4 ΔE 0.049
- Royal Blue #4169E1 ΔE 0.050
- Clear Blue #247AFD ΔE 0.051
- Soft Blue #6488EA ΔE 0.055
- Cerulean Blue #056EEE ΔE 0.058
- Cornflower #6A79F7 ΔE 0.062
Use #3F7CDD 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.