My friends and I did an "experiment" once with different kinds of tea. We each threw a fat quarter of muslin into the brew. We used red zinger for one, blackberry tea for another, etc. It was fun to see the different shades the muslin turned with different teas. We wrote the name of the tea on the selvage to keep for future reference.
I prefer to coffee dye. And you can get different shades with different brews of coffee too.