The Theta Chi chapter of Zeta Tau Alpha started as a local sorority, Delta Sigma Delta. The girls decided that they wanted to go national after seeing Chi Omega, Phi Mu (no longer at GMU), AOPi, and Sigma Kappa (folded within a year) settle on campus. They allowed the NPC groups to come tell the Delta Sig's what they could offer, and in the end a petition was written and sent to ZTA asking to become a chapter. On October 18, 1980, the Theta Chi chapter was born
I have no clue what their colors, symbols, or any of that were. It's impossible to search because Delta Sigma Delta is the name of a dental fraternity....