normal flora

Skin Flora

The varied environment of the skin results in locally dense or sparse populations, with Gram-positive organisms (e.g., staphylococci, micrococci, diphtheroids) usually predominating.

https://www.ncbi.nlm.nih.gov/books/NBK7617/

Gram-positive bacteria are bacteria classified by the color they turn in the staining method...The staining method uses crystal violet dye, which is retained by the thick peptidoglycan cell wall found in gram-positive organisms. This gives gram-positive organisms a blue color when viewed under a microscope.

https://www.ncbi.nlm.nih.gov/books/NBK470553/