My wound, when cleaned, is pink and moist. at center of the wound is a shallow dent where there once was a hole through which my mastoid muscle became infected (healed-antibio.). this spot is now dark red while the rest is pink. (internal bleeding?)?

Open wounds heal by forming what it called granulation tissue. This is typically pink and irregular and fills the defect from the base outward. Be cautious in cleaning the wound, to not disturb this tissue. Occasionally you may see the center appear dark red because of the increased vascularization that occurs during healing. This is not problematic unless you disturb the tissue and cause bleeding