The skin around a recent cat bite that was fairly deep is turning yellow close to the wound. Doctors had me in a splint and on antibiotics. Help?

Need to see. Would need to look at this to see what is going on, may just be scar tissue, but could indicate infection as well. Are you having pain, redness around the wound, or any draining fluid? These findings would favor a wound infection or pus under the skin.
See your doctor. Continue using the antibiotics as directed as well as your splint. Follow up with your primary care doctor to evaluate the wound and ensure proper healing.