GetColor32 = function (red, green, blue, alpha)
{
    return alpha << 24 | red << 16 | green << 8 | blue;
}
Given an alpha and 3 color values this will return an integer representation of it.

@function Phaser.Display.Color.GetColor32
@since 3.0.0

@param {number} red - The red color value. A number between 0 and 255.
@param {number} green - The green color value. A number between 0 and 255.
@param {number} blue - The blue color value. A number between 0 and 255.
@param {number} alpha - The alpha color value. A number between 0 and 255.

@return {number} The combined color value.