NEW DELHI: The colour is returning to the bling, and chances are that the new stones will remain a girl's best friend forever. From the Duchess of Cambridge - ever noticed her engagement ring? - and the Hollywood Alisters on Oscar night to the jewellery showrooms of Hong Kong and Zaveri Bazaar, rubies and emeralds are making a strong comeback in jewellery fashion as women bored with the white world of diamonds fall in love with coloured stones. Well, the diamond vs gem is a debate as old as the rocks. So just why are they back in the spotlight? As with all other fashion, the answer lies in the frothy mix of consumer desire, celebrity, and savvy marketing.