Checked, it works in Wille's Quake. Here's how to reproduce it:
I start GLQuake like this:
GLQuake -mem 32 -width 512 -game rpbot +map dm6
Then I goto multiplayer menu, set my shirt/pants to for example red, bring down the console, type "teamplay 1", then "map dm6" to restart the map.
When the map starts I bring down the console again, type for example "impulse 102". Shortly after 2 members of my team teleports in - but wearing the standard shirt/pants colors instead of the red one I'm wearing. (In Wille's Quake they wear red suits)