In an attempt to get the word out to my hometown, I thought I would be a nice guy and clean some bad looking shingles at the big church-gratis.  Well, I just got a call from the maintenance man commenting that the flashing has all kind of colors to it now and what exactly could I do about it.  It was a dull grey and now has an orangy tint which means to me it has oxidized.  I (we) thought that lead would make it pretty much impervious to any damage from the solution.  I told him that I would spray it again, this time coating it completely to at least make it uniform.  He THINKS that it is lead coated copper, but he isn't sure.

Any of you roofers/roof cleaners had experience with this?  I want to make this right.  I'm not feeling the warm fuzzies for the freebie at this time.   Maybe I am a chlorine cowboy splash and dash lowball turd?  I haven't felt like it until now...

Any advice would be appreciated!

I really really try to avoid damage to anything.  I am not a metallurgical expert, however.  I want to learn how to correct this problem and not make mistakes!

Thanks, 
Kurt