And an example
http://tatianastomatobase.com/wiki/Orange_Russian_117
The deliberate cross by Jeff Dawson was between
Russian 117,which is a large red heart
and
Georgia Streak,which is a bicolor
http://tatianastomatobase.com/wiki/Georgia_Streak
... and then grow out saved F2 seeds to start with and then make selections and keep doing that until you have something genetically stable.
It can take several years to do that.
Carolyn