Photoshop two-color blending formulas in JS based on: http://media.chikuyonok.ru/canvas-blending/
Basic usage:
multiply = blendingModes.multiply
pixelA =
r: 0
g: 60
b: 255
pixelB =
r: 45
g: 27
b: 134
pixelC =
r: multiply( pixelA.r, pixelB.r )
g: multiply( pixelA.g, pixelB.g )
b: multiply( pixelA.b, pixelB.b )