Complement colour

The Complement family of nodes takes the Input value and outputs that value subtracted from one:

 

Output = 1 minus Input

 

For colours the calculation is done on a component-wise basis, for example:

 

Output.red = 1 minus Input.red

Output.green = 1 minus Input.green

Output.blue = 1 minus Input.blue

 

These nodes are most useful when you are dealing with input values which go from 0 to 1. They can be useful for giving the effect of flipping or inverting a value, for example an input of 0.9 would become 0.1. If you were creating an effect using alpha blending you could use the Complement node to flip an alpha value from almost opaque to nearly transparent.