Red is the one wound color that’s a good sign — in the wound itself. Around the wound, it means something different.
In the wound. After cleaning or debridement, the area will be red or pink in color and look like fresh meat. A foot ulcer should be red or pink afterwards, and wounds that are pale, purple, or black are less likely to heal. A red wound bed is what healing tissue looks like.
Red is also part of the normal early sequence. Once the scab forms and your immune system begins protecting the wound, the wound becomes slightly swollen, red or pink, and tender — a stage lasting about 2 to 5 days.
Around the wound. Here redness is on every list of infection signs, and always as a change. More redness. Worsening redness. Redness and tenderness around the sore. Redness, increased warmth, or swelling around the wound.
And one kind that moves. With cellulitis, skin redness or inflammation gets bigger as the infection spreads, and a sore or rash can start suddenly and grow quickly in the first 24 hours.
There is one more kind, on a leg, that means something else again. With ischemic ulcers, dangling the leg down off the side of a bed or chair causes the leg to turn red, and raising it turns the leg pale and cool to touch. Redness that depends on position is a circulation finding, not an infection one.
The short version: red inside the wound is what healthy tissue looks like; red spreading outward from it is a sign to report.