Joe, Abe, and John Olsen have it pretty much correct.
Keep in mind that some interior pieces are only available in black today; the ability to source the myriad of different color choices that were present decades ago is gone. Yes you might find some stuff on ebay or what have you, but are you then replacing one 40 year old part for another 40 year old part?
Another thng to keep in mind in color changing is to do consider a "complete job". If you only do the seat covers, but the dash is original, or the padded bolster on the soft top tonneau, (ditto for a repaint), frankly it looks like an incomplete job. If you ever go to sell it (forgetting anything about price), these incomplete jobs present a lack of attention to detail, and beg the question "What ELSE wasn't done right"?