Burnt Red oxide. Don't be limited by boring grout colours, add this to your white grout for a great effect.
Iron Oxide - High UV stability, will not fade.
Mixing: Mix dry oxide to dry grout then add water, you may mix a little more oxide to the wet grout but ensure you mix very well. Once you have finished mixing let the grout slake for 5 minutes, mix again, then grout. Ensure you mix enough grout for your whole project, you may not be able to get the exact mix a second time.
Storage: Protect against weathering / Store in a dry place, Temperatures of above 80oC must be avoided
Safety: The product is not classified as hazardous under EC 1907/2006 & EC 1272/2008, however you should always wear a mask when mixing dry grout and oxide.
A little oxide goes a long way.