A description of the processing method used on Mariner IV test photos to transform shades of gray into shades of color to enhance their visibility. The tape came coded line by line with digits, from 0 for white to 63 for black. An IBM 7044 computer with S-C 4020 graphical plotter converted each frame of the tape to 64 separate frames, each corresponding to one shade of gray. The 64 frames were then copied successively onto one frame of Kodachrome, using color filters from red for 0 to blue for 63. The paper is illustrated with 9 photographs. The FORTRAN program and control cards are appended. (Prepared for presentation at the October 1967 annual meeting of UAIDE, Users of Automatic Information Display Equipment.) 28 pp. Ref.