https://www.foodnavigator.com/Article/2008/07/29/Natural-colours-catching-up-with-synthetic/ 2026-02-18T03:21:43.199Z always 0.5 https://www.foodnavigator.com/Article/2008/07/21/Oyster-friendly-microalgae-may-colour-food-blue-green/ 2024-11-02T06:04:01.922Z always 0.5