The green is only surface dirt, it will come off with a bit of scrubbing, I'd be tempted to go back to the sills after doing the frames and windows if they are that bad.
Con roof,
I wet several panels at a time, dip a brush into a bucket of water & multi purpose cleaner (cheap Own Brand) work into panels that are wet, then wash them off. Anything really stubborn, just go back to it after a few more panels.
Rob.