I have a burn wound that is turning yellow & red like small blood stains does that mean an infection is in it?

Colonized slough or: Yellow "stuff" at the base of the wound is likely "slough" (but w/o a picture, it's impossible to be sure). Slough is accumulated dead tissue, debris, dirt & bacteria. Small red "blood stains" could be blood vessels or healthy tissue. Bacteria are present all over the skin & colonize 100% of wounds, but infect (invade body & cause symptoms like fever, chills, nausea &c) in only a few. Wound Care!