redimage is a web app where you can make red images by parsing "sloppy mode" JavaScript formulas, with code being executed for every pixel.

x, y - integers indicating the position
m - integer that increments frame by frame
s - integer that indicates the value of the slider

ADDITIONAL FUNCTIONS and VALUES

hsv(h, s?, v?, mult?) - returns an RGB array. in this app, the hsv function has the 4th argument mult, which is the factor of the color values
invert(v, p?) - returns an RGB array, which is the inverted version of the 1st argument.

canvas.width, canvas.height - ...do i even need to explain

a list of codes made by various people.