All REDSHIFT scenarios are based on standard Orbiter (or addon) scenarios. However, REDSHIFT may fail to perform a mission, if you use the "original" scenario because most of the scenarios have been slightly modified to make them work with REDSHIFT.
The major change is that any space station listed in the "old" BEGIN_STATIONS / END_STATIONS block has been moved to the BEGIN_SHIPS / END_SHIPS section. REDSHIFT can't use stations, but requires vessels as reference objects during some of its operations (sepecially docking).
For all REDSHIFT missions (FOPs) contained in the distribution, there are scenarios defined in the Scenarios\REDSHIFT folder (or in one of the subdirectories) to be used for that mission. If you run into problems using a REDSHIFT mission, make sure you use the appropriate REDSHIFT scenario.