#5B73BC
Closest named color: Windows Blue (#3778BF). oklch(57% 0.116 268.8), rgb(91, 115, 188).
Aa
Black text reads best on this color (4.62:1).
About this color
#5B73BC is a medium-dark, moderately saturated blue. In OKLCH its lightness is 57%, its chroma 0.116 and its hue 269°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.037 away. Black text reads best on it, at 4.62:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | moderately saturated (0.116) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.62:1 |
| White text | 4.54:1 |
Values
| HEX | #5B73BC |
| RGB | rgb(91, 115, 188) |
| HSL | hsl(225, 42%, 55%) |
| OKLCH | oklch(57% 0.116 268.8) |
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 #5B73BC | 4.54:1 | AA | Lc -76.9 | Fine for body text |
| Black text on #5B73BC | 4.62:1 | AA | Lc 32.7 | Non-text elements, placeholder text |
| #5B73BC text on white | 4.54:1 | AA | Lc 71.4 | Content text, not long reading |
| #5B73BC text on black | 4.62:1 | AA | Lc -30.3 | Non-text elements, placeholder text |
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
#F3F5FA
oklch(97% 0.007 268.5)
-
Step 100
100
#E5EAF4
oklch(93.6% 0.015 264.5)
-
Step 200
200
#D1D9ED
oklch(88.5% 0.029 268.3)
-
Step 300
300
#B2C0E3
oklch(80.9% 0.052 268)
-
Step 400
400
#8B9FD6
oklch(70.8% 0.084 268.8)
-
Step 500
500
#6F86CB
oklch(63.1% 0.108 269.2)
-
Step 600
600 (this color)
#5B73BC
oklch(57% 0.116 268.8)
-
Step 700
700
#475C9E
oklch(49% 0.109 268.8)
-
Step 800
800
#3B4C80
oklch(42.8% 0.089 268.8)
-
Step 900
900
#323F67
oklch(37.6% 0.071 269.2)
-
Step 950
950
#1D253C
oklch(26.9% 0.045 268.7)
#5B73BC 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) | #567BBF | 0.021 |
| Deuteranopia (no green cones) | #4C72BA | 0.019 |
| Tritanopia (no blue cones) | #2F838E | 0.105 |
| Achromatopsia (no color) | #767676 | 0.117 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #5B73BC
#5B73BC
oklch(57% 0.116 268.8)
- #937300
#937300
oklch(57.1% 0.117 89.2)
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 #5B73BC, closest first.
No curated palette has a color within ΔE 0.04 of #5B73BC.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.037
- French Blue #436BAD ΔE 0.044
- Flat Blue #3C73A8 ΔE 0.048
- Steel Blue #4682B4 ΔE 0.050
- Cool Blue #4984B8 ΔE 0.051
- Off Blue #5684AE ΔE 0.057
- Dull Blue #49759C ΔE 0.058
- Muted Blue #3B719F ΔE 0.060
Use #5B73BC 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.