Instead of being a great big destructive event, galactic collisions can spawn massive ongoing cycles of stellar formation and rejuvenate a cosmic neighborhood.
As stars age they cool and turn yellow. When they are young they burn so hot and bright they burn blue. As can be seen the collision about 100 million years ago has spawned an entire sting of new stars in its wake as the gas clouds are able to gravitationally react with each other.
Even the spiral galaxies are showing new bursts of stellar formation.