Hi mystmaiden,

It rather depends on how close-up you want to get. If you're getting close enough to see individual hairs in the eyebrows then you'll probably have to create a texture. For "not-so-close-up", then just set the diffuse colour to whatever you want.

Depending on how detailed the trans-maps are you might be able to get away with plugging that into the diffuse and setting the colour to whatever you want the eybrows to be...
Cheers,
Diolma