Pics would help us a lot.

I unfortunately didn’t get any I was on a time crunch I just walked the house quickly then called the customer, the roof is currently yellowish/brown if that helps..he has power washed a small section himself which moldy exposed the green

My advice is to not clean it if he's expecting you to restore the green color. You can easily remove algae and pollen, but if you don't have experience removing oxidation on a metal roof, it's gonna be a miserable job and cost you way more time and money than you realize. And add to that not knowing if he'll even be satisfied with the result. He powerwashed a section as if to show you how it's done...that always bothers me a little too.

Yeah I’m thinking you’re right I hate to miss out on the money since I’m a weekend warrior for now, but I also need to walk away when the possibility of losing money is so prevalent