coolant in tank is blue, but under pressure cap is green - is something wrong?

I've not had the bike long and noticed the coolant in the expansion tank was a little low. Took off the fairings to refill it, and noticed that the coolant in the expansion tank is a blue colour, but when I take the pressure cap off (on the RH side) it is full of a bright green liquid. Is something blocked / wrong, or can this be normal? Could the thermostat be stuck shut or there be a blockage somewhere? Any advice appreciated.

 

Standard Honda coolant is blue. A number of aftermarket coolants are green. Possibly someone serviced the bike recently and replaced the coolant in the overflow tank with correct Honda coolant. It might take a while before complete mixing of the fluids takes place.
If the fluid was up to the top under the pressure cap I wouldn't be concerned. I would want to know who changed the fluid last and I'd want to know what they used. Maybe then I'd flush the system to be sure.