You'll notice that all the new -800 arrivals will be in the revised, enlarged Ryanair titles colours, the blue and yellow sweep line is more curved and the Flying Woman/Harp has a bigger bust!
Inside the cabin will have new seats that don't recline, have no seat back pockets, and have the Emergency Proceedure card permanently fixed to the seat back infront of you. A great idea for their operation, cutting down on time needed to prepare the cabin for the next departure.
Any aircraft you see at STN with "Hybrid" schemes are frames that have been inherited from Buzz, or taken on with a view to disposing them as the new -800's arrive.
As is true with easyJet with some of their ex-go frames - why waste money painting a unit that is heading out of the fleet within 12 months?