If the focal positions for red and blue is slight different inside
the prism as a result of passing thru the entry surface of the prism
(and the dispersion that goes with it). Then won't exiting from the
second surface bring back the focal positions to the original since it
is opposite in effect to air-glass in the 1st entry surface versus
glass-air in the 2nd entry surface??

No. Why? Because.

Roland Christen