Use this color calculation to reproduce a defined sRGB compositing, blending, luminance, or accessibility-contrast operation with explicit color inputs.

Source color

A three- or six-digit hexadecimal sRGB color.

Source opacity

Opacity of the source color between zero and one.

Backdrop color

A three- or six-digit hexadecimal sRGB color.

Backdrop opacity

Opacity of the backdrop color between zero and one.

Composite a source color over a backdrop color with straight-alpha source-over blending. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Composite color

Composite sRGB color in hexadecimal notation.

Composite alpha

Composite opacity between zero and one.

• Results depend on color space, transfer function, alpha convention, rounding, display profile, and the precise accessibility formula. Numeric contrast does not by itself establish readability for every user or interface state.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Verify the color-space and alpha assumptions, inspect the rendered result, and test relevant foreground, background, hover, disabled, and focus states. Pair contrast checks with broader accessibility review.

• Color Blend Calculator

  Blend two hexadecimal sRGB colors by interpolating their channels.

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