What color does the nail become when a bacterial or fungal infection reaches the end stage?

A nail infected with bacteria or fungus often exhibits a green coloration when it reaches the end stage of infection. This green color is typically the result of the presence of certain bacteria, particularly Pseudomonas aeruginosa, which produces pigments that can stain the nail. The greenish hue can also indicate a more serious infection process, where the infection is left untreated, allowing the bacteria or fungus to proliferate extensively.

Understanding the progression of nail infections is crucial in cosmetology, as it helps in identifying conditions that could affect nail health and client safety. This identification is key for cosmetologists to determine when to refer a client for medical attention, as continuing to work on an infected nail can exacerbate the issue or spread the infection to others. The other colors, although they may appear in different aspects of nail health or disease, do not specifically signify the advanced stage of a bacterial or fungal infection as the green color does.