Blends two colors into a single color.
Background— The background color (bottom layer) to blend.
Foreground— The foreground color (top layer) to blend.
Blend Mode— The way that the colors should be blended. For information about blend modes, see:
Foreground Opacity— The opacity that the foreground color should have in the blended color, ranging from 0 to 1.
Thanks to Romain Dura for reference implementations of many blend modes.
Keywords: add, additive, alpha, burn, channel, chroma, color, color burn, color dodge, combine, composite, darker, difference, divide, dodge, exclusion, fade, hard light, hard mix, hue, layer, light, lighter, linear burn, linear dodge, linear light, luminosity, merge, mix, multiply, normal, opacity, overlay, pin light, power, saturation, screen, soft light, subtract, tint, tone, transparency, transparent, vivid light