Wow, you really can't go wrong Mochi, but that rose gold is just yummy. Would mixing metals bother you? I do it all the time, rose gold cocktail ring and plat wedding bands and don't think anything of it, but some people are bothered by it. Your options all look great, so you really can't go wrong, nice dilemma eh?
Rhodolites (unless they''re overly dark, which this one isn''t) can look great in any metal - something very few gems can. I guess it''s a matter of the look you''re trying to achieve; a cold one (go with white), vibrant and hot (go with yellow), calm and soft (go with rose). It depends on the ring design too. If it''s something quite modern, you probably don''t want rose gold (you''ll probably go with white), but you''d like rose for a bit of an antique look, if that''s what you like. White would probably be the most elegant (and you could wear it most often), but I think few people would say a richly colored rhodolite doesen''t look great in, say, higher karat yellow. Go through your closet and see which colors you wear the most, and think about what would compliment them. You can also take your skin tone, and hair or eye color into consideration.
I don''t really have a particular color I wear....jeans and t-shirt kindda person, nothing fancy. Work is clothing is scrubs (AKA pajama). I think it''s sort of funny because I seem to put more thinking into stone settings than in what I''m going to be wearing.
Don''t really have a problem in mixing metals either, more the bettter!
If you don''t put much thought into wardrobe and don''t dress up very often, maybe it''s best to go for a striking combo with yellow gold. Either that, or a bi/tricolor setting.