#5B71CC
Closest named color: Windows Blue (#3778BF). oklch(57.5% 0.142 271.1), rgb(91, 113, 204).
Aa
Black text reads best on this color (4.67:1).
About this color
#5B71CC is a medium-dark, vivid blue. In OKLCH its lightness is 58%, its chroma 0.142 and its hue 271°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.046 away. Black text reads best on it, at 4.67:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | vivid (0.142) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.67:1 |
| White text | 4.48:1 |
Values
| HEX | #5B71CC |
| RGB | rgb(91, 113, 204) |
| HSL | hsl(228, 53%, 58%) |
| OKLCH | oklch(57.5% 0.142 271.1) |
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 #5B71CC | 4.48:1 | AA large text | Lc -76.4 | Fine for body text |
| Black text on #5B71CC | 4.67:1 | AA | Lc 33.1 | Non-text elements, placeholder text |
| #5B71CC text on white | 4.48:1 | AA large text | Lc 71.0 | Content text, not long reading |
| #5B71CC text on black | 4.67:1 | AA | Lc -30.7 | 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
#F3F5FB
oklch(97% 0.008 271.3)
-
Step 100
100
#E5E9F7
oklch(93.5% 0.019 273.2)
-
Step 200
200
#D0D8F1
oklch(88.4% 0.035 271.5)
-
Step 300
300
#B1BFEB
oklch(80.9% 0.064 271.1)
-
Step 400
400
#899DE1
oklch(70.7% 0.102 271.1)
-
Step 500
500
#6D83D8
oklch(63.1% 0.13 271.3)
-
Step 600
600 (this color)
#5B71CC
oklch(57.5% 0.142 271.1)
-
Step 700
700
#4659AB
oklch(49.1% 0.132 271)
-
Step 800
800
#3A498A
oklch(42.7% 0.109 271.4)
-
Step 900
900
#313E6E
oklch(37.7% 0.084 270.5)
-
Step 950
950
#1D2441
oklch(26.9% 0.055 272)
#5B71CC 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) | #497CCF | 0.032 |
| Deuteranopia (no green cones) | #3A72CA | 0.035 |
| Tritanopia (no blue cones) | #1B8594 | 0.127 |
| Achromatopsia (no color) | #777777 | 0.142 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #5B71CC
#5B71CC
oklch(57.5% 0.142 271.1)
- #937500
#937500
oklch(57.5% 0.118 90.8)
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 #5B71CC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.046
- Dark Periwinkle #665FD1 ΔE 0.047
- Royal Blue #4169E1 ΔE 0.051
- Slate Blue #6A5ACD ΔE 0.058
- French Blue #436BAD ΔE 0.059
- Light Indigo #6D5ACF ΔE 0.060
- Iris #6258C4 ΔE 0.062
- Cool Blue #4984B8 ΔE 0.068
Use #5B71CC 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.