HTML HSL and HSLA Colors
HSL stands for hue, saturation, and lightness. HSLA extends HSL with an Alpha channel, which sets opacity.
HSL Color Values
An HSL color is written as hsl(hue, saturation, lightness). Hue is a degree on the color wheel from 0 to 360, where 0 is red, 120 is green, and 240 is blue. Saturation is a percent, where 0% is gray and 100% is the full color. Lightness is a percent, where 0% is black and 100% is white.
Example
Six colors set with HSL values.
Output: complete HTML page
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Hsl Colors</title>
</head>
<body>
<h1 style="background-color:hsl(0, 100%, 50%);">hsl(0, 100%, 50%)</h1>
<h1 style="background-color:hsl(240, 100%, 50%);">hsl(240, 100%, 50%)</h1>
<h1 style="background-color:hsl(147, 50%, 47%);">hsl(147, 50%, 47%)</h1>
<h1 style="background-color:hsl(300, 76%, 72%);">hsl(300, 76%, 72%)</h1>
<h1 style="background-color:hsl(39, 100%, 50%);">hsl(39, 100%, 50%)</h1>
<h1 style="background-color:hsl(248, 53%, 58%);">hsl(248, 53%, 58%)</h1>
</body>
</html>
Saturation
Saturation is the intensity of a color. 100% is the pure color with no gray, 50% still shows the color but mixed with gray, and 0% is completely gray.
Example
One hue at decreasing saturation levels.
Output: complete HTML page
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Saturation</title>
</head>
<body>
<h1 style="background-color:hsl(0, 100%, 50%);">hsl(0, 100%, 50%)</h1>
<h1 style="background-color:hsl(0, 80%, 50%);">hsl(0, 80%, 50%)</h1>
<h1 style="background-color:hsl(0, 60%, 50%);">hsl(0, 60%, 50%)</h1>
<h1 style="background-color:hsl(0, 40%, 50%);">hsl(0, 40%, 50%)</h1>
<h1 style="background-color:hsl(0, 20%, 50%);">hsl(0, 20%, 50%)</h1>
<h1 style="background-color:hsl(0, 0%, 50%);">hsl(0, 0%, 50%)</h1>
</body>
</html>
Lightness
Lightness is how much light the color has: 0% is no light (black), 50% is neither dark nor light, and 100% is full light (white).
Example
One hue at increasing lightness levels.
Output: complete HTML page
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Lightness</title>
</head>
<body>
<h1 style="background-color:hsl(0, 100%, 0%);">hsl(0, 100%, 0%)</h1>
<h1 style="background-color:hsl(0, 100%, 25%);">hsl(0, 100%, 25%)</h1>
<h1 style="background-color:hsl(0, 100%, 50%);">hsl(0, 100%, 50%)</h1>
<h1 style="background-color:hsl(0, 100%, 75%);">hsl(0, 100%, 75%)</h1>
<h1 style="background-color:hsl(0, 100%, 90%);">hsl(0, 100%, 90%)</h1>
<h1 style="background-color:hsl(0, 100%, 100%);">hsl(0, 100%, 100%)</h1>
</body>
</html>
Shades of Gray
Shades of gray are made by setting hue and saturation to 0 and changing only the lightness.
Example
Six shades of gray made with HSL.
Output: complete HTML page
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Gray Shades</title>
</head>
<body>
<h1 style="background-color:hsl(0, 0%, 20%);">hsl(0, 0%, 20%)</h1>
<h1 style="background-color:hsl(0, 0%, 30%);">hsl(0, 0%, 30%)</h1>
<h1 style="background-color:hsl(0, 0%, 40%);">hsl(0, 0%, 40%)</h1>
<h1 style="background-color:hsl(0, 0%, 60%);">hsl(0, 0%, 60%)</h1>
<h1 style="background-color:hsl(0, 0%, 70%);">hsl(0, 0%, 70%)</h1>
<h1 style="background-color:hsl(0, 0%, 90%);">hsl(0, 0%, 90%)</h1>
</body>
</html>
HSLA Color Values
HSLA extends HSL with an Alpha channel that sets opacity. It is written as hsla(hue, saturation, lightness, alpha), where alpha is a number from 0.0 (fully transparent) to 1.0 (fully opaque).
Example
One color shown at six opacity levels with HSLA.
Output: complete HTML page
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Hsla Colors</title>
</head>
<body>
<h1 style="background-color:hsla(9, 100%, 64%, 0);">hsla(9, 100%, 64%, 0)</h1>
<h1 style="background-color:hsla(9, 100%, 64%, 0.2);">hsla(9, 100%, 64%, 0.2)</h1>
<h1 style="background-color:hsla(9, 100%, 64%, 0.4);">hsla(9, 100%, 64%, 0.4)</h1>
<h1 style="background-color:hsla(9, 100%, 64%, 0.6);">hsla(9, 100%, 64%, 0.6)</h1>
<h1 style="background-color:hsla(9, 100%, 64%, 0.8);">hsla(9, 100%, 64%, 0.8)</h1>
<h1 style="background-color:hsla(9, 100%, 64%, 1);">hsla(9, 100%, 64%, 1)</h1>
</body>
</html>