1. Cherry red skin colour symptom is not evident in low and mild cases, but evident in severe (near death) and fatal cases.
Advanced Assessment and Treatment of Trauma, by American Academy of Orthopaedic Surgeons, pag. 195:
2. Cherry red skin colour appears late in CO poisoning (severe and lethal cases) and is an inconsistent symptom (not usually see in low and mild cases).
Note: in the bellow quote AMS means Acute Mountain Sickness , HACE means High Altitude Cerebral Edema, HARH means High Altitude Retinal Hemorrhage.
Title Resource Utilization and Development: A Perspective Study of Madhya Pradesh, India, by Shri Kamal Sharma, pag. 849:
3. Cherry red skin colour is associated with CO poisoning.
Forensic Science: An Encyclopedia of History, Methods, and Techniques, by William J. Tilstone, Kathleen A. Savage, Leigh A. Clark, pag. 99:
4. Cherry red skin colour is described as "pink coloration of the nail beds and skin at high saturation levels" (severe cases) and "usually only apparent in the areas of post mortem lividity" (lethal cases).
Air Pollution and Health, edited by Stephen T. Holgate, Hillel S. Koren, Jonathan M. Samet, Robert L. Maynard, pag. 770:
5. Cherry red skin colour is uncommon (low and mild cases) and can help the diagnosis of CO poisoning. Acute manifestation of CO poisoning also includes retinal hemorrhage.
Samuels's Manual of Neurologic Therapeutics, edited by Martin A. Samuels, Allan H. Ropper, pag. 518:
6. Cherry red skin colour becomes dark green and then brown with the onset of decomposition (several hours after death).
Spitz and Fisher's Medicolegal Investigation of Death: Guidelines for the, edited by Werner U. Spitz, Daniel J. Spitz, Russell S. Fisher, pag. 840:
7. Cherry red skin colour results from continual exposure to high concentrations of CO regardless of death (livor mortis).
Forensic Pathology of Trauma, By Michael J. Shkrum, David A. Ramsay, pag. 291:
8. Cherry red skin colour is a characteristic colour of CO poisoning in some cases.
Lewis' Dictionary of Toxicology, By Robert Alan Lewis, pag. 228:
9. Cherry red skin colour helps to diagnose CO poisoning in living patients (severe cases) and in autopsies (lethal cases).
USMLE Platinum Notes Step 1, By Ashfaq UI Hassan, pag. 142:
10. Cherry red skin colour is the keyword for CO poisoning although the pale skin is more commonly seen rather than the cherry red skin (low and mild cases).
Dermatology Terminology, By Herbert B. Allen, pag. 178:
NOTE: notice the cherry red skin colour on the shoulders and torso in the living patient: