#3F70C0
Closest named color: Windows Blue (#3778BF). oklch(55.1% 0.136 259.7), rgb(63, 112, 192).
Aa
White text reads best on this color (4.89:1).
About this color
#3F70C0 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 55%, its chroma 0.136 and its hue 260°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.022 away. White text reads best on it, at 4.89:1.
| Hue family | Blues |
| Lightness | medium-dark (55%) |
| Chroma | moderately saturated (0.136) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.29:1 |
| White text | 4.89:1 |
Values
| HEX | #3F70C0 |
| RGB | rgb(63, 112, 192) |
| HSL | hsl(217, 51%, 50%) |
| OKLCH | oklch(55.1% 0.136 259.7) |
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 #3F70C0 | 4.89:1 | AA | Lc -79.1 | Fine for body text |
| Black text on #3F70C0 | 4.29:1 | AA large text | Lc 30.4 | Non-text elements, placeholder text |
| #3F70C0 text on white | 4.89:1 | AA | Lc 73.6 | Content text, not long reading |
| #3F70C0 text on black | 4.29:1 | AA large text | Lc -28.1 | 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
#E3EAF6
oklch(93.5% 0.018 261.3)
-
Step 200
200
#CCDAF0
oklch(88.5% 0.034 259.4)
-
Step 300
300
#AAC2E9
oklch(80.9% 0.061 260.1)
-
Step 400
400
#7CA2DE
oklch(70.8% 0.098 259.3)
-
Step 500
500
#5B89D4
oklch(63.1% 0.124 259.8)
-
Step 600
600 (this color)
#3F70C0
oklch(55.1% 0.136 259.7)
-
Step 700
700
#325FA7
oklch(49.1% 0.126 259.4)
-
Step 800
800
#2A4E87
oklch(42.7% 0.104 259.2)
-
Step 900
900
#26416C
oklch(37.6% 0.081 259.3)
-
Step 950
950
#17263F
oklch(26.9% 0.051 260.2)
#3F70C0 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) | #4B77C3 | 0.024 |
| Deuteranopia (no green cones) | #366BBE | 0.017 |
| Tritanopia (no blue cones) | #00828E | 0.110 |
| Achromatopsia (no color) | #717171 | 0.136 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F70C0
#3F70C0
oklch(55.1% 0.136 259.7)
- #956900
#956900
oklch(55.2% 0.114 79.7)
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 #3F70C0, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.022
- French Blue #436BAD ΔE 0.030
- Mid Blue #276AB3 ΔE 0.034
- Flat Blue #3C73A8 ΔE 0.041
- Nice Blue #107AB0 ΔE 0.048
- Muted Blue #3B719F ΔE 0.054
- Royal Blue #4169E1 ΔE 0.056
- Steel Blue #4682B4 ΔE 0.059
Use #3F70C0 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.