Redwood Foods versions of these are sold in Holland and Barrett, Asda and wholefoods shops. Gravy granules. Just because you're feeding a vegetarian or vegan doesn't mean they have to have 'vegetarian' gravy (you know, the thin watery stuff that looks like a dissolved vegetable stock cube).
If your tongue is stained black or dark brown it may be caused by medications and certain foods/drinks. Drinking several cups of coffee or tea per day may stain the tongue; some people who supplement with green drinks containing chlorophyll may notice a very green tongue.
Learn more about hairy tongue. Lichen planus. Lichen planus is a rash-like condition that can cause tongue discoloration. Usually lichen planus on the tongue occurs as a white color. It can change green when bacteria or yeast begins to grow on it, certain foods or drinks are consumed, or certain products are used. Other symptoms of lichen planus include: