To generate a video in greyscale, enter a function f(x,y,t). For example:

sin(x-t)*cos(y+t)

To generate a video in color, enter a function f(x,y,r,g,b,t). For example:

r*sin(x-t)+g*cos(y+t)+b*(x+y+t)

The video has an x, y, and t range of -10, 10. x and y refer to the horizontal and vertical axis, while t refers to the time in the video. At the beginning of the video, t is -10; at the end, t is 10. The z range is -1, 1. This means if your function evaluates to -1 at a pixel, it will be as dark as possible. If it evaluates to 0, it will be at half brightness. If it evaluates to 1, it will be full brightness. Because 0 is half brightness, you must subtract colors to get rid of them from a video. Here is an example of an entirely red video:

r*sin(x+t)-g-b

The math functions available are on display to the left. Here is documentation for them. Some python constructs are also available (if, in, etc.) if you can figure out how to use them. Some restrictions apply. Have fun!