I agree that it looks like surface rust. I would try to just wipe it down with a good cleaner then follow it with chain lubricant. I use a plastic brush to clean my chain because I am afraid of a wire brush damaging an o-ring. It might be unfounded but using a plastic brush can't hurt. A plastic brush not as aggressive but a good degreaser helps make chain cleaning manageable.
Agreed. Just get a nice cotton towel with some good chain lube and keep wiping until it starts coming off. It doesn't look major as long as you get it off as soon as you can. Then make sure you lube it really well afterwards.
Got this from another website...
"there are a couple of ways to check to see if the chain is merely surface rust or the chain is in need of being replaced.
find a way to lift the rear tire off the ground, center stand or side stand with bike leaned over... spin the tire and watch the chain as it gones on and comes off the sprockets to see if there is any popping of the links. if there is a popping or kinking appearance, this could be a couple of things... lack of lubrication or the chain is stretched. if you have access to some chain lub, lub the chain and continue to spin to see if the lub frees up the links to where they quit popping / kinking. if they quit, it's probably merely surface rust from the last washing of the bike and the chain was not lub'd well following.
another indicator is to look at the chain tensioners on the back of the swing arm. if the tensioners appear to be to where they can not apply more tension on the chain, the chain is probably stretched to close to it's limit. some times if the chain seems to roll smoothly (from first point), you might be able to merely remove a link and re-adjust the tension.
also, try moving the chain side to side to see how much free play there is. there shouldn't be much side play if the chain is in decent condition.
also look at the sprockets to see if there is any cupping in the teeth on the side that would get the power force of the chain.
see if you can determine whether the chain is a standard type chain or an o-ring style. the o-ring style chain would be highly unlikely to have internal damage from rust and merely cosmetic appearance."