I have a red middle toe that was once bruised so i changed shoes and (i exercise a lot) and three months later toe is still red and always sore!

See a foot doc: Fracture, bursitis, infection, tendonitis are all part of the differential diagnosis.

Have you considered: Seeing a podiatrist to have your toe checked or seeing a pedorthist to ensure your shoes fit you properly?

Get a medical examin: An examination from your physician is necessary to be sure that you do not have growth or tumor affecting this area. An x-ray may be indicated. It could also be low grade infection. But only a physical exam from your doctor can sort it out. Do not delay it anymore as you already have watched it long enough.