Use the GIMP to edit this file. You should leave the black box on the bottom because that's where the 3 thumbnails of MPEGS will be drawn.
The titles of the MPEGS will be drawn across the screen near the bottom of the white area. The titles are drawn in white text with a black box enclosing the text, so any colors are fine for the white area. I suggest using dumpmpeg to get a frame dump of the show title screen and using that in the white area.