#577BC4
Closest named color: Windows Blue (#3778BF). oklch(58.9% 0.12 263.3), rgb(87, 123, 196).
Aa
Black text reads best on this color (5.03:1).
About this color
#577BC4 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.120 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.035 away. Black text reads best on it, at 5.03:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.120) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 5.03:1 |
| White text | 4.17:1 |
Values
| HEX | #577BC4 |
| RGB | rgb(87, 123, 196) |
| HSL | hsl(220, 48%, 55%) |
| OKLCH | oklch(58.9% 0.12 263.3) |
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 #577BC4 | 4.17:1 | AA large text | Lc -74.1 | Content text, not long reading |
| Black text on #577BC4 | 5.03:1 | AA | Lc 35.5 | Non-text elements, placeholder text |
| #577BC4 text on white | 4.17:1 | AA large text | Lc 68.6 | Content text, not long reading |
| #577BC4 text on black | 5.03:1 | AA | Lc -33.1 | 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 600.
-
Step 50
50
#F3F5FA
oklch(97% 0.007 268.5)
-
Step 100
100
#E4EAF5
oklch(93.6% 0.016 262.8)
-
Step 200
200
#CFDAEE
oklch(88.6% 0.03 262.5)
-
Step 300
300
#AFC1E4
oklch(80.9% 0.053 263.7)
-
Step 400
400
#85A1D7
oklch(70.8% 0.086 263.2)
-
Step 500
500
#6688CC
oklch(63% 0.11 263.3)
-
Step 600
600 (this color)
#577BC4
oklch(58.9% 0.12 263.3)
-
Step 700
700
#3F5E9F
oklch(49% 0.111 263.6)
-
Step 800
800
#344D81
oklch(42.6% 0.092 263.6)
-
Step 900
900
#2D4168
oklch(37.8% 0.072 262.8)
-
Step 950
950
#1B263D
oklch(27% 0.046 264.1)
#577BC4 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) | #5D82C7 | 0.021 |
| Deuteranopia (no green cones) | #5077C2 | 0.015 |
| Tritanopia (no blue cones) | #118B96 | 0.107 |
| Achromatopsia (no color) | #7C7C7C | 0.120 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #577BC4
#577BC4
oklch(58.9% 0.12 263.3)
- #9F7506
#9F7506
oklch(58.9% 0.12 83.1)
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 #577BC4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.035
- Cool Blue #4984B8 ΔE 0.037
- Steel Blue #4682B4 ΔE 0.039
- Off Blue #5684AE ΔE 0.048
- Water Blue #0E87CC ΔE 0.052
- Dusty Blue #5A86AD ΔE 0.053
- Flat Blue #3C73A8 ΔE 0.057
- Faded Blue #658CBB ΔE 0.057
Use #577BC4 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.