#577BD3
Closest named color: Windows Blue (#3778BF). oklch(59.8% 0.141 265.6), rgb(87, 123, 211).
Aa
Black text reads best on this color (5.17:1).
About this color
#577BD3 is a medium-dark, vivid blue. In OKLCH its lightness is 60%, its chroma 0.141 and its hue 266°. 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 5.17:1.
| Hue family | Blues |
| Lightness | medium-dark (60%) |
| Chroma | vivid (0.141) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 5.17:1 |
| White text | 4.05:1 |
Values
| HEX | #577BD3 |
| RGB | rgb(87, 123, 211) |
| HSL | hsl(223, 58%, 58%) |
| OKLCH | oklch(59.8% 0.141 265.6) |
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 #577BD3 | 4.05:1 | AA large text | Lc -73.1 | Content text, not long reading |
| Black text on #577BD3 | 5.17:1 | AA | Lc 36.5 | Non-text elements, placeholder text |
| #577BD3 text on white | 4.05:1 | AA large text | Lc 67.6 | Content text, not long reading |
| #577BD3 text on black | 5.17:1 | AA | Lc -34.1 | 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 500.
-
Step 50
50
#F2F5FC
oklch(97% 0.01 267.4)
-
Step 100
100
#E3EAF8
oklch(93.6% 0.02 264.5)
-
Step 200
200
#CDD9F3
oklch(88.4% 0.038 265.8)
-
Step 300
300
#ABC0EE
oklch(80.8% 0.069 265.7)
-
Step 400
400
#809FE6
oklch(70.8% 0.11 265.7)
-
Step 500
500 (this color)
#577BD3
oklch(59.8% 0.141 265.6)
-
Step 600
600
#486DCC
oklch(55.6% 0.153 265.7)
-
Step 700
700
#395AB0
oklch(49% 0.142 265.6)
-
Step 800
800
#304A8F
oklch(42.7% 0.118 266)
-
Step 900
900
#2A3F72
oklch(37.8% 0.091 265.4)
-
Step 950
950
#192543
oklch(27% 0.058 266.1)
#577BD3 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) | #5484D6 | 0.023 |
| Deuteranopia (no green cones) | #4479D1 | 0.021 |
| Tritanopia (no blue cones) | #008F9D | 0.123 |
| Achromatopsia (no color) | #7E7E7E | 0.141 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #577BD3
#577BD3
oklch(59.8% 0.141 265.6)
- #A07900
#A07900
oklch(59.8% 0.122 85.9)
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 #577BD3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.046
- Soft Blue #6488EA ΔE 0.049
- Dark Sky Blue #448EE4 ΔE 0.052
- Cool Blue #4984B8 ΔE 0.055
- Water Blue #0E87CC ΔE 0.056
- Steel Blue #4682B4 ΔE 0.059
- Cornflower #6A79F7 ΔE 0.061
- Royal Blue #4169E1 ΔE 0.061
Use #577BD3 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.