Color Formats, Gradients and Transparency

What Is It?

CSS supports named colors, hexadecimal, RGB, and HSL values. Alpha changes color transparency without fading all descendants.

Properties, Tags and Attributes Explained

• rgb(): Describes red, green, and blue channels; an optional slash sets alpha.
• hsl(): Describes hue, saturation, and lightness; an optional slash sets alpha.
• opacity: Fades the entire element including its descendants.
• radial-gradient(): Creates color stops radiating from a center.
• conic-gradient(): Creates color stops around an angle.
• currentColor: Uses the computed color property value.

Each example is a complete HTML page. The CSS is inside the head's style element. Use Try in new tab to edit the CSS or HTML, run your changes, and reset the example.

Example 1: Transparent fill

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Color Formats, Gradients and Transparency</title>
  <style>
    .demo { background: #dbeafe; padding: 16px; }
    p { background: rgb(124 58 237 / 20%); padding: 12px; color: hsl(260 70% 25%); border: 2px solid currentColor; }
  </style>
</head>
<body>
  <div class="demo"><p>Only the background color has alpha.</p></div>
</body>
</html>

What you see: The translucent purple fill leaves the text and border fully opaque.

Example 2: Radial gradient

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Color Formats, Gradients and Transparency</title>
  <style>
    .demo { height: 140px; background: radial-gradient(circle at top left, #fef08a, #f97316); }
  </style>
</head>
<body>
  <div class="demo"></div>
</body>
</html>

What you see: The gradient radiates from the top left.

Example 3: Conic gradient

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Color Formats, Gradients and Transparency</title>
  <style>
    .demo { width: 140px; height: 140px; border-radius: 50%; background: conic-gradient(#2563eb 0 60%, #e2e8f0 60% 100%); }
  </style>
</head>
<body>
  <div class="demo" role="img" aria-label="60 percent complete"></div>
</body>
</html>

What you see: The circle has a blue 60 percent segment with an accessible text description.

When and Where to Use It

Use alpha for overlays, HSL for adjusting hue or lightness, and gradients for decoration or a chart with an equivalent text description.

Common Mistake or Useful Tip

Changing opacity on a parent also fades its children; use an alpha background when the text should stay opaque.

Try It Yourself

Change the conic split to 75% and update its text description too.