Congratulations on your new pet.  It is always best when you have a new pet to have him/her examined by a veterinarian to ensure he/she is in good health.  It sounds like you have a concern, which even further validates a visit to your veterinarian.  Feces color depends on what the pet is eating and the health they are exhibiting.  You need to have them seen by your veterinarian to be certain he/she is healthy.