We do business casual too, but some months we are asked to accent it with our colors. One month, we have a 'khaki day' when we wear our letter khaki shirts. And usually for the last meeting of the Sorority year we all wear our favorite pari. My favorite pari is a grey t-shirt with SGR in block greek letters and the letters are colored in the state of Texas flag. These are the iron on/stich on letters where the bottom (outline) is one color and the top is another. So, the sigma is blue with a white star, then the gamma and rho both have blue backgrounds(bottom outline), and the top color is 1/2 white on top and 1/2 red on bottom. If you look at the Texas flag, then this discription will make more sense.
When I first joined grad chapter I stepped into our June meeting with shorts on. You know Houston, 100 F and 100% humidity. They were nice khaki shorts and they fell just above the knee. Boy, did I get yelled at for doing that!!!!

Alot of the older Sorors expect full 'Sunday' dress: calf length dress, stockings, heels and maybe a hat. Eventually we elected a younger administration and they relaxed the dress code a bit.