Sorry, can't help with Photoshop much. But back in the day (old school biker days), we'd take a photo of the bike and then take an exacto knife and cut the tank, and side panels; then put different colored paper behind the photo. Mix and match until you liked it, then you had your paint scheme.
There are a lot of shades of blue in that picture to choose from, I don't think this is going to be the affect your looking for, but for a quick job it may give you an ideal. Maybe someone else with more time can hook you up.