setPixel
.setPixel( x, y, red, green, blue )
Sets new colour values for the pixel located at the given x/y location. This only updates the red, green and blue values; the alpha value of the pixel is not altered.
Each component red, green and blue component should be a value from 0 to 255.
.setPixel( x, y, red, green, blue, alpha )
The same as above, only this allows you to also alter the alpha value.
The alpha value should be between 0.0 and 1.0.
