Dear Fred;
I bet you are sick of trying to read yellow text against a white background too ! Go into Assist, Mechanical Options, Standards, On the list of ansi features right click layer objects, select properties, change the color of the layer that is used for feature control frames. Dont ask me which it is. I cannot remember right now. But I did fix this in a recent job i did which required GDT. Another fix involves changing the screen background colour to black so the yellow frames are easy to read. One warning if your drawing will ever be opened in autocad V14 bear in mind all the symbols in your feature control frames will dissapear. You will have to recreate them using blocks in version 14. Been there, done that.
Regards Adrian