Maybe its own topic, but how were coves painted? Were they noted on BMIHT sheets? I believe my BJ8 was originally Colorado Red (only), but black coves were either added by the dealer or at one of its repaints--it was metallic bronze(!) for a while--and there is a noticeable edge along the cove where it was applied after-the-fact (won't a wrap do this too?). I once saw described a technique for painting coves such that they blended together, leaving little/no edge. IIRC, it involved painting the coves first, then masking the coves and edges before applying the main color, then removing the masking at exactly the right drying state so that the main color paint could just barely flow into the cove edge, leaving no discernible edge between the two (or possibly a minuscule overlap). 'Two-Tone' paint was popular for American cars in the 50s and 60s but, usually, a trim strip was added over the border as doing a perfect blend would be too labor ($$$) intensive. Off-the-top-of-my-head I can't think of any modern cars with two-tone paint (they only seem to come in black, silver or white).
My opinion, worth absolutely nothing, is that only red or white with black coves or white with some other colors--BRG, Florida Green, Healey Blue, etc.--looks good. Owners are free to choose, of course, but like yellow cars it may affect resale (if that matters). Note metallic bronze, while a popular 'hot rod' color back when got painted 'resale red' over black. But resale may be a non-issue for most of us I suspect. I believe most all 100Ms were OEW, and came with black coves.