#3970B4
Closest named color: French Blue (#436BAD). oklch(54.1% 0.122 255), rgb(57, 112, 180).
Aa
White text reads best on this color (5.05:1).
About this color
#3970B4 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 54%, its chroma 0.122 and its hue 255°. Its hue sits on the cool side of the wheel. The nearest named color is French Blue (#436BAD), ΔE 0.017 away. White text reads best on it, at 5.05:1.
| Hue family | Blues |
| Lightness | medium-dark (54%) |
| Chroma | moderately saturated (0.122) |
| Temperature | cool |
| Nearest name | French Blue (#436BAD) |
| Black text | 4.15:1 |
| White text | 5.05:1 |
Values
| HEX | #3970B4 |
| RGB | rgb(57, 112, 180) |
| HSL | hsl(213, 52%, 46%) |
| OKLCH | oklch(54.1% 0.122 255) |
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 #3970B4 | 5.05:1 | AA | Lc -80.1 | Fine for body text |
| Black text on #3970B4 | 4.15:1 | AA large text | Lc 29.4 | Dividers and decoration only |
| #3970B4 text on white | 5.05:1 | AA | Lc 74.7 | Content text, not long reading |
| #3970B4 text on black | 4.15:1 | AA large text | Lc -27.0 | 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
#F2F6FA
oklch(97.1% 0.007 247.9)
-
Step 100
100
#E3EBF5
oklch(93.7% 0.016 253.9)
-
Step 200
200
#CCDBEE
oklch(88.6% 0.031 254.3)
-
Step 300
300
#A9C3E4
oklch(80.9% 0.055 254.5)
-
Step 400
400
#7BA3D7
oklch(70.6% 0.088 255.3)
-
Step 500
500
#598CCC
oklch(63.2% 0.112 254.8)
-
Step 600
600 (this color)
#3970B4
oklch(54.1% 0.122 255)
-
Step 700
700
#2F629F
oklch(49.2% 0.113 254.4)
-
Step 800
800
#285081
oklch(42.7% 0.094 254.7)
-
Step 900
900
#254368
oklch(37.8% 0.073 254.6)
-
Step 950
950
#16273D
oklch(27% 0.047 255.4)
#3970B4 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) | #5175B7 | 0.030 |
| Deuteranopia (no green cones) | #3F69B3 | 0.019 |
| Tritanopia (no blue cones) | #008089 | 0.097 |
| Achromatopsia (no color) | #6F6F6F | 0.122 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3970B4
#3970B4
oklch(54.1% 0.122 255)
- #956300
#956300
oklch(54% 0.114 74.6)
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 #3970B4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- French Blue #436BAD ΔE 0.017
- Flat Blue #3C73A8 ΔE 0.023
- Mid Blue #276AB3 ΔE 0.024
- Windows Blue #3778BF ΔE 0.025
- Muted Blue #3B719F ΔE 0.034
- Nice Blue #107AB0 ΔE 0.035
- Dull Blue #49759C ΔE 0.046
- Ocean Blue #03719C ΔE 0.050
Use #3970B4 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.