Contrasting Alpha

What It Does

The Contrasting Alpha node adjusts a color's transparency until it reaches a target contrast ratio with a background. It uses binary search to find the optimal alpha value that provides the desired contrast level.

Inputs

Name	Description	Type	Required
Foreground	The color to adjust transparency for	Color	No
Background	The background color to test contrast against	Color	No
Algorithm	Contrast calculation method (APCA is default)	String	No
Threshold	Target contrast value to achieve	Number	No
Precision	Number of binary search iterations (higher = more precise)	Number	No

Outputs

Name	Description	Type
Alpha	The calculated alpha value (0-1)	Number
Color	The resulting color with adjusted transparency	Color
Contrast	The actual contrast ratio achieved	Number

How to Use It

1. Drag the Contrasting Alpha node into your graph.

2. Connect a foreground color (like #737272) and background color (like #FFF).

3. Set your desired contrast threshold (default: 60).

4. Adjust precision if needed (default: 5 iterations).

5. The node outputs the color with adjusted alpha, the alpha value, and the resulting contrast.

Tips

• Higher precision values give more accurate results but may increase processing time.

• This node is useful for ensuring text remains readable while maintaining some transparency.

See Also

• Contrast: For measuring contrast between two colors.

• Contrasting Color: For selecting between two colors based on contrast.

• Flatten Alpha: For removing transparency from a color.

Use Cases

• Semi-Transparent UI Elements: Create overlay panels that maintain text readability.

• Accessible Design: Ensure text with transparency meets accessibility standards.

• Dynamic Backgrounds: Automatically adjust text opacity based on varying background colors.