When I first joined IAABO, over thirty years ago, we wore gray shirts with blue piping, and, I believe, a blue collar. Pants could be blue, or black, belted, or beltless. Jacket was blue satin with gray piping. Even though the blue pants were a better match, the "cool" guys wore black pants because college officials wore black pants.
I was still wearing my old, outdated, gray undershirts to do yard work up until a few years ago, until they turned threadbare, and just plum wore out.