#5B66A5
Closest named color: French Blue (#436BAD). oklch(52.9% 0.1 275), rgb(91, 102, 165).
Aa
White text reads best on this color (5.40:1).
About this color
#5B66A5 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 53%, its chroma 0.100 and its hue 275°. Its hue sits on the cool side of the wheel. The nearest named color is French Blue (#436BAD), ΔE 0.031 away. White text reads best on it, at 5.40:1.
| Hue family | Blues |
| Lightness | medium-dark (53%) |
| Chroma | moderately saturated (0.100) |
| Temperature | cool |
| Nearest name | French Blue (#436BAD) |
| Black text | 3.88:1 |
| White text | 5.40:1 |
Values
| HEX | #5B66A5 |
| RGB | rgb(91, 102, 165) |
| HSL | hsl(231, 29%, 50%) |
| OKLCH | oklch(52.9% 0.1 275) |
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 #5B66A5 | 5.40:1 | AA | Lc -82.2 | Fine for body text |
| Black text on #5B66A5 | 3.88:1 | AA large text | Lc 27.2 | Dividers and decoration only |
| #5B66A5 text on white | 5.40:1 | AA | Lc 76.8 | Fine for body text |
| #5B66A5 text on black | 3.88:1 | AA large text | Lc -24.9 | 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
#F4F5FA
oklch(97.1% 0.007 277.2)
-
Step 100
100
#E7E9F3
oklch(93.5% 0.014 277.1)
-
Step 200
200
#D4D8EA
oklch(88.5% 0.025 275.9)
-
Step 300
300
#B8BFDE
oklch(80.9% 0.044 275.3)
-
Step 400
400
#939ECE
oklch(70.8% 0.071 274.4)
-
Step 500
500
#7985C1
oklch(63.1% 0.092 274.8)
-
Step 600
600 (this color)
#5B66A5
oklch(52.9% 0.1 275)
-
Step 700
700
#525C95
oklch(49.2% 0.092 275)
-
Step 800
800
#434B79
oklch(42.7% 0.077 275.2)
-
Step 900
900
#383F61
oklch(37.7% 0.059 274.4)
-
Step 950
950
#212539
oklch(27% 0.038 274.9)
#5B66A5 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) | #4F6DA8 | 0.023 |
| Deuteranopia (no green cones) | #4967A4 | 0.023 |
| Tritanopia (no blue cones) | #42737D | 0.089 |
| Achromatopsia (no color) | #6A6A6A | 0.100 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #5B66A5
#5B66A5
oklch(52.9% 0.1 275)
- #7E6A18
#7E6A18
oklch(52.9% 0.099 94.5)
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 #5B66A5, closest first.
No curated palette has a color within ΔE 0.04 of #5B66A5.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- French Blue #436BAD ΔE 0.031
- Dusky Blue #475F94 ΔE 0.043
- Flat Blue #3C73A8 ΔE 0.046
- Muted Blue #3B719F ΔE 0.048
- Dull Blue #49759C ΔE 0.052
- Mid Blue #276AB3 ΔE 0.055
- Denim #3B638C ΔE 0.059
- Metallic Blue #4F738E ΔE 0.061
Use #5B66A5 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.