When using this mode, RGB channels are uniformly multiplied, always resulting in a darker image (layering the base layer pixel with the corresponding top layer pixel)
Similar to multiple, but uses 2 inversion passes to RGB channels, resulting in a brighter picture.
A combination of the two, both increasing color intensity but also brightening the overall image. The darker areas of the base layer utilizes augments to darker values and the light areas of the top layer are likewise augmented brighter, almost using an HDR approach.
Ease of Use:
Scale of 1 to 5; 1 being easiest, 5 being hardest