Its personal taste is but if you plan on using it in tournaments then I prefer black and sand/tan (name depends on vendor). After that I would go with black and white.
Color Combinations of Basic Club Plastic Sets.

I just see these as fun sets that you could mix and match for club play. Tournament I wouldn't use them but for a casual setting I would.

To make chess more fun and exciting to my young family members I have purchased some funky color combos. Pink/white, blue/white, purple/pink, bright green and white and one red/blue.
The red/blue was probably the only one I didnt like. No natural dark side vs light side.

I have done Yellow & Black. My latest one is Aqua (Teal) & Orange. It actually looks cool on a Brown & White board.

Here is that Aqua(Teal) & Orange color combination I mentioned earlier. I really like the colors of this set and the Saddle Brown Flex Pad really complements both colors. Teal is Black and Orange is White.
I am really happy that they have the options to get a weighted Basic Club set in so many colors. I got my set from wholesalechess. The board I got from chesshouse.
https://www.wholesalechess.com/shop/chess-pieces/plastic-chess-pieces/heavy-tournament-chess-pieces-color-half-set
https://www.chesshouse.com/collections/club-style-chess-boards/products/flex-pad-club-chess-board?variant=34089254913
With all the different colors that are offered to mix and match up with. What is the best color combination or worst color combination you have seen?