A black whisker on a cat is normal and nothing to worry about.
Whiskers, also called vibrissae, are specialized sensory hairs that help cats perceive. It’s not unusual for them to be different colors, like black. Similar to coat color, whisker color is determined by pigmentation.
There’s usually nothing to worry about as long as the black whiskers appear healthy and normal in length and texture. However, it’s best to consult a veterinarian if you notice any abnormalities or damage to the whiskers of your feline.