Here is an X-Wing I repainted in the colours of Green Squadron.
Like most of my X-Wing repaints, I didn’t strip the model but painted over it. To match the FFG colour, I used old GW paints. I mixed Komando Khaki and a little bit of Rotting Flesh. The cockpit can be touched up with some Elf Grey. If you don’t have those out of print paints, you can match them to newer ones by using painting charts found with a google search.
The brown was done with a few random brown ink washes. For the life of me I can’t remember what green paint I used for the squadron markings or what grey I used for the hull plate repairs, so I apologize for that. A gentle green can be seen on my Armada A-Wings found here complete with instructions on how to achieve it.