Mixes color flows together according values of an array.
Array which contains a set of values from 0 to 1.
The first value of the array determines the amount of the first color flow
The second value of the array determines the amount of the second color flow, etc...
If mix value is the array [0.2,0.5,0.6,0.1] then
out = 0.2 * colorIn1 + 0.5 * colorIn2 + 0.6 * colorIn3 + 0.1 * colorIn4
Color flows to mix.
Output result, as a mix of color inputs according the mix values array.
Ignore the alpha channel in the color mix result.