The puzzle consists of a series of squares that change color when the puzzle is reloaded.
The green value of each square increases by one every time the square changes color. The red and blue values of each square cycle through a series of values. Plotting the red value along the x-axis and the blue value along the y-axis, plots a series of points that outline the shape of a letter. Each square represents one letter and the squares are arranged in alphabetical order.
Each square changes color at a different rate (one changes once per second, one changes once every 2 seconds, etc). Arranging the squares in this order gives the message THIS GREEN IS BETWEEN WHITECHAPEL AND MILE END. Stepney Green is the London Tube station between Whitechapel and Mile End so the answer is STEPNEY.