To expound on the previous post, working with X-plane repaints is a good way to tinker with paint schemes and get a better preview of them than the three-view drawings provide. There's a bit of a learning curve involved, but in the end it amounts to editing a flat image file that the X-plane tools will then wrap around a 3d model. For the image editing, you use whatever your favorite editor is; for wrapping around a model, there's a utility that comes with X-plane (even the free version) for previewing a model, or you can load your custom paint livery into the game.
This is what the flat image looks like:
It takes a little trial and error to figure out what everything is (example: which fuselage profile is the left and which is right?), but in the end you just color to your heart's desire. When you're done, you can load the resulting livery into their 3d model previewer, which looks like this:
In there, you can roll/pitch/yaw the preview to your heart's content, and for extra realism, you can then go actually fly your aircraft in X-Plane and make sure it looks good while performing questionable acts of aeronautical decision making in the vicinity of your home airport:
There's only one thing you must
pay for to do this, and that's the RV-8 X-Plane add-on; it's $32. The rest you can do with free stuff, though what you can do in the game with your completed livery is limited unless you buy the full X-plane version.
Overall, it's surprisingly straightforward to do. There are lots of tutorials floating around for doing liveries, and I got the basics worked in in a few hours - but I'm probably more tech comfortable than many people.