KC135 yes the first thing that came to mind when I saw it was Marine One. Not that the scheme is any Marine One that I have seen, but the dark green/white with straight edges not camo'ed is something I've only ever seen on Marine 1. However.. it wasn't the normal scheme, Obama isn't in Florida, and there was just the one solo, so I highly doubt it.
As far as Colombia yes I've seen them, Carson, Erikson, HeavyLift, etc during the fires here in '98 but as you say Columbia usually has white with red stripe, I've never seen them green, and there is no fire emergency that I know of on the east coast of Florida.
Not arguing with you, good points all, but I'm inclined to think it maybe something different. Or I may just be wrong