I did a complete color change to a 98 and did it with a donor car in the color I wanted.
To do a painted interior properly you will need to remove any/all parts you want to do, clean them with ajax and mineral spirits, then do normal prep and hit them with the correct color matched SEM dye.
Now I'm not trying to be discouraging or say don't do it, it can be done and when done right its like OEM, but just know that its not just a day of taping off interior pieces and spraying them and done.
2000 Mustang GT Steeda build #48. Bolt ons, suspension, Novi 2000.
Just because I give you advice, doesn't mean I know more than you. Its just means I've done more stupid ****.