Different ways pixels can blend with the pixels behind them.
|alpha||Colors will be mixed based on alpha.|
|add||Colors will be added to the existing color, alpha will not be changed.|
|subtract||Colors will be subtracted from the existing color, alpha will not be changed.|
|multiply||All color channels will be multiplied together, producing a darkening effect.|
|lighten||The maximum value of each color channel will be used.|
|darken||The minimum value of each color channel will be used.|
|screen||The opposite of multiply: the pixel colors are inverted, multiplied, and inverted again, producing a lightening effect.|