Origins

Andorians are blue skinned aliens with two antenna on the top of their foreheads and white hair.  They used to be enemies of the Vulcans but eventually became part of the Federation of Planets along with the Vulcans and Humans.  Andorians are know for being warriors, and all of them spend their lives with the goal of becoming warriors.  The Warrior class is highly honored among their people.  The woman of their culture are just as much valued as warriors as the men and are usually the same height or taller.
 
Musicians are also highly honored in the Andorian culture.  This is due to there antennas being receptive to a broad amount of tone that would be unheard by human ears.  Music was used as the first Andorian language on their planet as well. 

Creation

Andorians were created for the original Star Trek series in the mid to late 1960's.  They were later seen in the Star Trek Animated Series and as background charters in some of the films but other than novels and comics characters from this race were rarely used.  This was the same for the series that followed until the television show Enterprise.
 
In the Televistion Show Enterprise the Andorians were introduced and the character Shran became very popular.  It was even discussed that in the fifth season Shran would become a regular character on the show.  Unfortunately the show was canceled after the fourth season.