Chiffon picks up colours in a completely different way from silk. Rich jewel colours such as emerald, sapphire, and burgundy work especially well in chiffon because the fabric has a natural luminous quality that amplifies colour instead of swallowing it up. Soft pastel shades like blush, sage, and ivory in chiffon Banarasi saree  work wonderfully too, giving off a more delicate effect than the exact same shades would in silk. Both extremes work, and you definitely need them both.