Xiaomi will start selling the White Mi 6 tomorrow.
The White variant will come in the same 6GB+64GB and 6GB+128GB configurations and will cost 2,499 Yuan (€323;£285;$368) and 2,899 Yuan (€375;£330;$427) respectively.
Since launching the Mi 6 in April Xiaomi has been offering three models - Black and Coral Blue as well as the Ceramic variant, which sold out very quickly. You still can't buy the Silver Mi 6 though and according to previous reports it ended up a tough manufacturing challange so it may never actually get released.
Thanks for the tip, Steve!