#5166B4
Closest named color: French Blue (#436BAD). oklch(53.1% 0.125 270.4), rgb(81, 102, 180).
Aa
White text reads best on this color (5.37:1).
About this color
#5166B4 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 53%, its chroma 0.125 and its hue 270°. Its hue sits on the cool side of the wheel. The nearest named color is French Blue (#436BAD), ΔE 0.024 away. White text reads best on it, at 5.37:1.
| Hue family | Blues |
| Lightness | medium-dark (53%) |
| Chroma | moderately saturated (0.125) |
| Temperature | cool |
| Nearest name | French Blue (#436BAD) |
| Black text | 3.90:1 |
| White text | 5.37:1 |
Values
| HEX | #5166B4 |
| RGB | rgb(81, 102, 180) |
| HSL | hsl(227, 40%, 51%) |
| OKLCH | oklch(53.1% 0.125 270.4) |
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 #5166B4 | 5.37:1 | AA | Lc -81.9 | Fine for body text |
| Black text on #5166B4 | 3.90:1 | AA large text | Lc 27.5 | Dividers and decoration only |
| #5166B4 text on white | 5.37:1 | AA | Lc 76.6 | Fine for body text |
| #5166B4 text on black | 3.90:1 | AA large text | Lc -25.2 | 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
#F3F5FB
oklch(97% 0.008 271.3)
-
Step 100
100
#E5EAF5
oklch(93.6% 0.016 266.3)
-
Step 200
200
#D1D9EE
oklch(88.6% 0.03 269.1)
-
Step 300
300
#B2C0E6
oklch(81% 0.056 269.2)
-
Step 400
400
#8B9ED9
oklch(70.7% 0.089 270.3)
-
Step 500
500
#6F85CF
oklch(63.1% 0.115 270.3)
-
Step 600
600 (this color)
#5166B4
oklch(53.1% 0.125 270.4)
-
Step 700
700
#485BA2
oklch(49.1% 0.116 270.4)
-
Step 800
800
#3B4B83
oklch(42.8% 0.095 270)
-
Step 900
900
#323F69
oklch(37.7% 0.074 269.6)
-
Step 950
950
#1E253E
oklch(27.1% 0.048 271.1)
#5166B4 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) | #456FB7 | 0.026 |
| Deuteranopia (no green cones) | #3966B2 | 0.027 |
| Tritanopia (no blue cones) | #1C7784 | 0.112 |
| Achromatopsia (no color) | #6A6A6A | 0.125 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #5166B4
#5166B4
oklch(53.1% 0.125 270.4)
- #846900
#846900
oklch(53.2% 0.109 91)
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 #5166B4, closest first.
No curated palette has a color within ΔE 0.04 of #5166B4.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- French Blue #436BAD ΔE 0.024
- Mid Blue #276AB3 ΔE 0.041
- Flat Blue #3C73A8 ΔE 0.048
- Iris #6258C4 ΔE 0.050
- Windows Blue #3778BF ΔE 0.051
- Dusky Blue #475F94 ΔE 0.054
- Muted Blue #3B719F ΔE 0.055
- Dark Periwinkle #665FD1 ΔE 0.058
Use #5166B4 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.