Decals For Colour Change - Is It Possible?

I would consider how the bike would look without decals. Sometimes completely smooth is the way to go.

 

Ring round a couple of your local sign/vehicle graphics shops. If you can do some legwork and provide artwork files (needs to be a vector file, not a bitmap like .jpeg, .png etc) although they may have what you need already if they've done a similar job before. If we had the file or was supplied it we'd charge 20-30 quid for a pair of tank decals in vinyl cut.

 

Mine has Matt tape over the coloured decals and a carbon low can. Looks good and stealthy (to me anyway .. ) so why not get it painted first . Then see . You can always cut out coloured paper and design your own and get made by a vinyl printer if you like the decals. Make it unique..

 

OP you want to look for vehicle wrap products. 3M has a color graphic line. Like @ChasChas says, vehicle graphics shop is the ticket. However, do your research on the installer. It takes skill with razors and applying with no air bubble or lift. I heard horror stories of razor cuts into the paint on high end cars from bad installers.