Update: I did not get the above reply and I was tired of hearing the chick squeal when the hen nipped at it. The hen is in a brooder box with the chicks as it is too cold here to have them in the coop yet. I dyed the chick, using a mix of green, blue and red food color. It was not easy to apply the food color--I put it in a teacup and put the chick in there and used my fingers to dob it on (toothbrush and cotton ball did not work). My hands got nice and brown too. Then I stuck the chick back under the hen to dry. Anyway, success! I got the chick brown enough that the hen leaves it alone, and it is able to be out with the other chicks rather than cowering beneath her all the time. The serama is raising a mix of chicks, seramas and easter eggers (and who knows what the father was as I have a mix of roos).