Well the gray, blue and red 2 tone seats are stock in most Rangers so that's why people have them. Also not to many people add green LED's as accent lighting or to the dash or gauge's because accent lighting would look ricey and cheap looking and the stock lights are already green so it kind of defeats the purpose of swapping to green other then having them brighter.
About the seats, you can buy seat covers and have them made how ever you want but they will never be as good looking in regards to how there made and put together compared to the stock seats.
Ford Ranger EDGE
Drivetrain: 8.8 LS w/ 4.10's
Exterior Mods: 06+ Emblems
Audio: 500 RMS Kenwood Amp, 10" Kenwood Shallow Sub