I have a 91 SE, with blue interior and 60/40 bench seats. I want to switch to dark grey bucket seats, and interior. Should i paint the old stuff, or get it covered in leather?

Recovering the seats with new leather would be the way I'd go. You can paint the plastic parts with the right prep products and paint from SEM. Carpet... well, there are franchise buisnesses that dye home carpeting so I guess it can be done. If I recall correctly, that blue color carpet is pretty dark already so going to a dark gray may not be possible.

Try a junkyard or someone parting out an 87-91 SSE with the gray interior. It'* very light and will become dark gray with no problem.

https://www.accmats.com/crl/ShoppingCart.aspx

link to ACC who makes molded carpet replacements. any color you want

It would be best to begin with a factory carpet and then color. I bought a replacement from that company and it took two two tries to get a carpet to fit. I sent the OEm carpet to them so they could update the mold they use.

While I was impressed at the way they handled my situation and overall happy with the new carpet, it still didn't fit like the OEM.