As I recall in 77 there were 5 colors for the exterior of converts and 3 for sedans. Convertibles were Super Beetles and sedans were "Basic Beetles" now called "Custom" or "Deluxe" beetles. All had the "Cloud White" headliner as stated above.
Converts were
L20A Chrome Yellow w/Black top & Interior
L31B Mars Red W/black/black
L52k Barrier Blue w/light sand (off white/gray) top & Parchment (light tan) interior
L90B Polar White ( creamy - off white almost like the 60's Pearl white) w/black/black
The Champaign edition debut this year in Alpine (bright) white with light sand top and "85U" Opal ( off white ) interior.
For sedans there were the following colors, all Metallic to give the last models imported a little pizzaz. Although the announcement wasn't made until fall that these were the last sedans to come to the USA.
L96N Lime green (which wasn't the same color as the 75 Legrande Bugs) these had a "Tobacco" brown interior, kind of a washed out brown color
L97A Diamond Silver with black interior
L99F Bahama Blue with the same Opal interior as the Champagne edition convertible although VW called it "Cameo" in the sedan.
Now with that said, it was not uncommon for the dealer to swap interiors in beetles for a quick sale if a customer wanted a different color so there could be a Diamond Silver 77 beetle out there with a Cameo interior in it although I doubt is as this sounds pretty hideous.