#3971B7
Closest named color: French Blue (#436BAD). oklch(54.5% 0.125 255.2), rgb(57, 113, 183).
Aa
White text reads best on this color (4.97:1).
About this color
#3971B7 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 54%, its chroma 0.125 and its hue 255°. Its hue sits on the cool side of the wheel. The nearest named color is French Blue (#436BAD), ΔE 0.021 away. White text reads best on it, at 4.97:1.
| Hue family | Blues |
| Lightness | medium-dark (54%) |
| Chroma | moderately saturated (0.125) |
| Temperature | cool |
| Nearest name | French Blue (#436BAD) |
| Black text | 4.21:1 |
| White text | 4.97:1 |
Values
| HEX | #3971B7 |
| RGB | rgb(57, 113, 183) |
| HSL | hsl(213, 53%, 47%) |
| OKLCH | oklch(54.5% 0.125 255.2) |
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 #3971B7 | 4.97:1 | AA | Lc -79.6 | Fine for body text |
| Black text on #3971B7 | 4.21:1 | AA large text | Lc 29.9 | Dividers and decoration only |
| #3971B7 text on white | 4.97:1 | AA | Lc 74.2 | Content text, not long reading |
| #3971B7 text on black | 4.21:1 | AA large text | Lc -27.5 | 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
#E3EBF5
oklch(93.7% 0.016 253.9)
-
Step 200
200
#CCDBEE
oklch(88.6% 0.031 254.3)
-
Step 300
300
#A9C3E5
oklch(80.9% 0.056 255.2)
-
Step 400
400
#7AA3D8
oklch(70.6% 0.09 255.1)
-
Step 500
500
#588BCE
oklch(63% 0.116 255.7)
-
Step 600
600 (this color)
#3971B7
oklch(54.5% 0.125 255.2)
-
Step 700
700
#2E61A1
oklch(49% 0.117 255.4)
-
Step 800
800
#275082
oklch(42.7% 0.095 254.7)
-
Step 900
900
#254269
oklch(37.6% 0.076 256.3)
-
Step 950
950
#16273D
oklch(27% 0.047 255.4)
#3971B7 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) | #5176BA | 0.030 |
| Deuteranopia (no green cones) | #3F6AB6 | 0.019 |
| Tritanopia (no blue cones) | #00818B | 0.098 |
| Achromatopsia (no color) | #707070 | 0.125 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3971B7
#3971B7
oklch(54.5% 0.125 255.2)
- #966500
#966500
oklch(54.5% 0.115 75.7)
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 #3971B7, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- French Blue #436BAD ΔE 0.021
- Windows Blue #3778BF ΔE 0.021
- Flat Blue #3C73A8 ΔE 0.026
- Mid Blue #276AB3 ΔE 0.027
- Nice Blue #107AB0 ΔE 0.035
- Muted Blue #3B719F ΔE 0.038
- Dull Blue #49759C ΔE 0.049
- Steel Blue #4682B4 ΔE 0.053
Use #3971B7 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.