Its impossible, unless i believe there is way to do it using JASS, havent done jass in years so i wouldnt know for sure but i have seen maps where it was blue or purple or black etc, however through the normal editor i am 100% positive its impossible.
I'm on a page about incorrect corrections, and spent the better part of like two hours trying to get someone to understand that -5^2 = -25, not 25, and then that post had comments get reposted because that group is self sustaining, and that person was in turn trying to explain what I just explained to them. And I'm taking that as a victory
I will be AFK for a couple of days you guys hold down the fort while I am gone. I will be checking in on my phone but that will severly limit me. Be back saturday!