#577AC8
Closest named color: Windows Blue (#3778BF). oklch(59% 0.126 264.6), rgb(87, 122, 200).
Aa
Black text reads best on this color (5.02:1).
About this color
#577AC8 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.126 and its hue 265°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.036 away. Black text reads best on it, at 5.02:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.126) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 5.02:1 |
| White text | 4.18:1 |
Values
| HEX | #577AC8 |
| RGB | rgb(87, 122, 200) |
| HSL | hsl(221, 51%, 56%) |
| OKLCH | oklch(59% 0.126 264.6) |
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 #577AC8 | 4.18:1 | AA large text | Lc -74.1 | Content text, not long reading |
| Black text on #577AC8 | 5.02:1 | AA | Lc 35.4 | Non-text elements, placeholder text |
| #577AC8 text on white | 4.18:1 | AA large text | Lc 68.6 | Content text, not long reading |
| #577AC8 text on black | 5.02:1 | AA | Lc -33.0 | 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
#E4EAF5
oklch(93.6% 0.016 262.8)
-
Step 200
200
#CFD9EF
oklch(88.4% 0.032 266.1)
-
Step 300
300
#AEC1E6
oklch(80.9% 0.056 263.7)
-
Step 400
400
#84A0DA
oklch(70.7% 0.091 264.3)
-
Step 500
500
#6687D0
oklch(63% 0.117 264.8)
-
Step 600
600 (this color)
#577AC8
oklch(59% 0.126 264.6)
-
Step 700
700
#3F5DA3
oklch(49.1% 0.118 264.9)
-
Step 800
800
#344C84
oklch(42.6% 0.098 265)
-
Step 900
900
#2D406A
oklch(37.7% 0.076 264.6)
-
Step 950
950
#1B263E
oklch(27.1% 0.048 264.7)
#577AC8 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) | #5981CB | 0.019 |
| Deuteranopia (no green cones) | #4B77C6 | 0.017 |
| Tritanopia (no blue cones) | #058B97 | 0.114 |
| Achromatopsia (no color) | #7C7C7C | 0.126 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #577AC8
#577AC8
oklch(59% 0.126 264.6)
- #9E7600
#9E7600
oklch(58.9% 0.121 84.8)
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 #577AC8, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.036
- Cool Blue #4984B8 ΔE 0.043
- Steel Blue #4682B4 ΔE 0.046
- Water Blue #0E87CC ΔE 0.053
- Off Blue #5684AE ΔE 0.055
- Dusty Blue #5A86AD ΔE 0.060
- Flat Blue #3C73A8 ΔE 0.061
- Dark Sky Blue #448EE4 ΔE 0.061
Use #577AC8 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.