A helpful feature would be to assign colors to different processes used to create multi-colored, single-extruded prints, so easy identification of start/stop layers can be made, to assist with visual confirmation of the final print, when the multiple processes are combined for layer build simulation. This might be done as a different option to assigning colors to the various tool path depictions currently shown.
This feature is now available in the new Version 4.0 software! Once you enter the Preview Mode, you can change the coloring mode to "Current Process". This will display a different color for each section the print that is created with different processes. The legend in the top left will display the name of each process beside the color that is used for that process.