Tea and coffee will be just as permanent as the original color (which might have been tea or coffee) and are easy to rinse out if the color isn't right. Dyes like those derived from pomegranate seed will be more stable, but correction is difficult.
Brown teas can be made lighter or darker by thinning (any brand Darjeeling or Earl Grey) Red Rose and herbals show more pink or green shades.
Darker browns require Starbucks Christmas Blend.
Or Safeway instant.