Scientists had theorized that a color photograph could be created
by combining red, green and blue light, but the first person to
prove the idea was James Clerk Maxwell (1831-1879).
Maxwell created the first color photograph by combining three
black and white versions of the same image. Each image
passed through a different color filter (red, green and blue)
before exposing a single screen.
Maxwell, James Clerk, & Sutton, Thomas. Tartan Ribbon – 1861. Wikimedia Commons. Accessed: 22 July 2010.