Stupid blisters!

My blister has returned. If you recall, a while back I had two blisters. One was really big, the other was small and barely even bothered me. The big one healed a while ago. You can still see where it was, but it's all healed up. The smaller one has returned with a vengeance. While the big one was peeling off, the small one calloused. I thought I would just have a bump there, but about a week ago, the callous peeled off. It didn't really bother me until today. I had an early morning run of 5 miles. I noticed a twinge where the blister was, and when I got done running and looked at it, it looked pretty bad. It was bubbled up again and this time it's red. I drained it and put a band aid over it. Does the red mean that it's infected? I need to look into that. I'm supposed to be getting a new pair of shoes soon, since I've getting close to 300 miles on the ones I have. Hopefully the new pair won't give me blisters!