Short answer...yes there are sprays and dyes that you can use.
Longevity for using aerosols to spray panels is questionable...I would say that prep is key for the product to bond with the vinyl, but I have not seen any that really last. For a convertible that gets a lot of damaging sun rays, I'm not sure it would be very good.
Leatherique has very good products for leather/vinyl seat repair and re-dying - if I was to try and dye panels and seats myself...that would be the product I'd try. There's lots of successful results I've seen from DIY'ers....the 944 and 911 guys have many projects posted over the years for seat and interior re-virginization.
Problem with re-dying is if you scuff the panel, the lighter base may show through if the dye didn't really bite in to the material.
Finding replacement panels in the colour you want is likely the best but toughest option, as locating the panels in decent shape in the colour you want is probably like finding a needle in a haystack.
Recovering is another option, although the most expensive. However it would give the best results.
This is a tough project to take on, but fun at the same time.
Good luck sir, post your pics.