Re: Pre TOS star cruiser....
Well, phaser bulbs on the refit had yellow coatings around them. I always theorized it to be some sort of anti-burn or anti-abrasive coating, designed to allow permeability out (to release heat and radiation) but perhaps not in.
"If you can't take a little bloody nose, maybe you ought to go back home and crawl under your bed. It's not safe out here. It's wondrous, with treasures to satiate desires both subtle and gross; but it's not for the timid." - Q