#3F70CA
Closest named color: Windows Blue (#3778BF). oklch(55.7% 0.149 261.4), rgb(63, 112, 202).
Aa
White text reads best on this color (4.79:1).
About this color
#3F70CA is a medium-dark, vivid blue. In OKLCH its lightness is 56%, its chroma 0.149 and its hue 261°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.030 away. White text reads best on it, at 4.79:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | vivid (0.149) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.38:1 |
| White text | 4.79:1 |
Values
| HEX | #3F70CA |
| RGB | rgb(63, 112, 202) |
| HSL | hsl(219, 57%, 52%) |
| OKLCH | oklch(55.7% 0.149 261.4) |
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 #3F70CA | 4.79:1 | AA | Lc -78.4 | Fine for body text |
| Black text on #3F70CA | 4.38:1 | AA large text | Lc 31.1 | Non-text elements, placeholder text |
| #3F70CA text on white | 4.79:1 | AA | Lc 72.9 | Content text, not long reading |
| #3F70CA text on black | 4.38:1 | AA large text | Lc -28.7 | 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
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E3EAF7
oklch(93.6% 0.019 263)
-
Step 200
200
#CCDAF3
oklch(88.6% 0.038 262.1)
-
Step 300
300
#A9C2ED
oklch(81% 0.067 261.2)
-
Step 400
400
#7BA1E4
oklch(70.8% 0.107 261.3)
-
Step 500
500
#5988DC
oklch(63.2% 0.137 261.2)
-
Step 600
600 (this color)
#3F70CA
oklch(55.7% 0.149 261.4)
-
Step 700
700
#315DAE
oklch(49.1% 0.138 261.4)
-
Step 800
800
#294C8D
oklch(42.6% 0.115 261.5)
-
Step 900
900
#254071
oklch(37.7% 0.09 261.4)
-
Step 950
950
#162642
oklch(27% 0.057 260.9)
#3F70CA 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) | #4479CD | 0.025 |
| Deuteranopia (no green cones) | #2A6CC8 | 0.022 |
| Tritanopia (no blue cones) | #008593 | 0.121 |
| Achromatopsia (no color) | #727272 | 0.150 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F70CA
#3F70CA
oklch(55.7% 0.149 261.4)
- #956B00
#956B00
oklch(55.6% 0.115 81.4)
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 #3F70CA, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.030
- Royal Blue #4169E1 ΔE 0.041
- French Blue #436BAD ΔE 0.045
- Mid Blue #276AB3 ΔE 0.045
- Flat Blue #3C73A8 ΔE 0.056
- Nice Blue #107AB0 ΔE 0.060
- Dark Periwinkle #665FD1 ΔE 0.061
- Cerulean Blue #056EEE ΔE 0.062
Use #3F70CA 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.