I am probably going to paint it the cream color that it already is, just freshen it up. I may had a little brown trim around the windows. I don't know what a chicken safe paint would be, but I think what is on it is just an exterior house paint. I will most likely paint it while they are inside. It shouldn't take long to dry where it will not hurt them.
I read earlier where you mentioned keeping the hen house locked when they are in, the door is shut and latched, to things can not get into them. We don't have a lot of predator problems here, really. I have a motion light on the hen house that comes on when something is out there, and it usually scares things off. One time we did have an opossum in the hen house, but it got in before we closed the door that night. It was looking for eggs. My husband found it hiding under the nest boxes and got rid of it. It never bothered the hens, or we got there in time to keep it from bothering them. With our dogs around, most critters stay away.