The color blend node can be used to blend between two or more colors.
Color 0..N
The colors to mix. These ports are numbered as Color 0, Color 1 etc. When a color is specified a new input will be created for the next color.
Blend value
This specifies how the input colors will be blended. The inputs colors are interpolated linearly so a Blend Value of 0 will result in the color of the input port Color 0 and a value of 1 will result in Color 1.
A value of 0.5 will be a mix of 50% of Color 0 and Color 1, a number of 1.5 will be a mix between Color 1 and Color 2, etc. Values below 0 or above the amount of input colors are clamped to the closest color.
Result
The resulting blended color