Since my trailer is red and my window frame is white, I got a can of red spraypaint, masked the glass with painters tape and a grocery bag, and changed the color.
The tricks to spray painting are:
1) warm temperature. Make sure the can and the area are 60F or more
2) not too humid. I prefer it below 80%
3) keep the can moving! If you hover over a spot too long, you will get runs.
4) spray lightly. If you do not get perfect coverage on one light pass (and you won't) make another light pass at another angle.
Even coverage without runs is the goal.