I use 1 tablespoon dried hibiscus flowers for every 2 cups of water and steep about 10 minutes.) (eatingcleanrecipes.com)
To prepare brown - grey, or blue - grey dye: Use about 2/3 cup of dry hibiscus flowers to 1 1/2 cups of water, and brew for 15 minutes. (viktoriastable.com)
In a small saucepan, bring 1 cup of water and 1/2 cup dried hibiscus flowers to a boil. (theothersideofthetortilla.com)