Sometimes my sons is absolutely green!! I have taken him to the doctor insisting that he must have an infection. He told me that sometimes with sever allergies they can have green drainage and sometimes even run a low grade temp. To ease my mind though he ordered antibiotics which helped for maybe a week and then he was off and pouring again! We now try to help control cough (albuterol syrup) and he said not to worry about the runny nose. Did she take him to the dr. at all or she assuming that it is allergies? as long as he has seen the dr. I would be pretty confident that it is not contagious.