#577AD1
Closest named color: Windows Blue (#3778BF). oklch(59.5% 0.139 265.8), rgb(87, 122, 209).
Aa
Black text reads best on this color (5.10:1).
About this color
#577AD1 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.139 and its hue 266°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.044 away. Black text reads best on it, at 5.10:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.139) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 5.10:1 |
| White text | 4.10:1 |
Values
| HEX | #577AD1 |
| RGB | rgb(87, 122, 209) |
| HSL | hsl(223, 57%, 58%) |
| OKLCH | oklch(59.5% 0.139 265.8) |
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 #577AD1 | 4.10:1 | AA large text | Lc -73.5 | Content text, not long reading |
| Black text on #577AD1 | 5.10:1 | AA | Lc 36.1 | Non-text elements, placeholder text |
| #577AD1 text on white | 4.10:1 | AA large text | Lc 68.0 | Content text, not long reading |
| #577AD1 text on black | 5.10:1 | AA | Lc -33.6 | 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
#E4EAF8
oklch(93.7% 0.02 267.3)
-
Step 200
200
#CDD9F3
oklch(88.4% 0.038 265.8)
-
Step 300
300
#ACC0EE
oklch(80.9% 0.069 266.5)
-
Step 400
400
#809FE5
oklch(70.7% 0.109 265.5)
-
Step 500
500 (this color)
#577AD1
oklch(59.5% 0.139 265.8)
-
Step 600
600
#496DCB
oklch(55.6% 0.151 265.9)
-
Step 700
700
#3A5AAF
oklch(48.9% 0.141 265.9)
-
Step 800
800
#304A8E
oklch(42.6% 0.117 265.9)
-
Step 900
900
#2A3F71
oklch(37.7% 0.09 265.2)
-
Step 950
950
#192542
oklch(27% 0.057 265.8)
#577AD1 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) | #5483D4 | 0.024 |
| Deuteranopia (no green cones) | #4478CF | 0.022 |
| Tritanopia (no blue cones) | #008D9B | 0.122 |
| Achromatopsia (no color) | #7D7D7D | 0.139 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #577AD1
#577AD1
oklch(59.5% 0.139 265.8)
- #9F7800
#9F7800
oklch(59.5% 0.122 85.7)
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 #577AD1, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.044
- Soft Blue #6488EA ΔE 0.053
- Cool Blue #4984B8 ΔE 0.054
- Dark Sky Blue #448EE4 ΔE 0.055
- Water Blue #0E87CC ΔE 0.056
- Steel Blue #4682B4 ΔE 0.057
- Royal Blue #4169E1 ΔE 0.060
- Cornflower #6A79F7 ΔE 0.063
Use #577AD1 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.