Strabismus surgery does have some complicating diseases, they are naturally and medically normal, and you do not have worry too much, but in order to make everything is secure, you have to seriously obey your doctor's advices.
Here are some professional points:
Appearing red just as you mentioned, is definitely typical , and it will just disappear normally one month following the surgery. However, exception cases may occur on condition the processes or ways of the surgery are different or even they are not safe.
For safety's sake, you'd better turn to your doctor one month later if your eyes stay red.