This is Mur 
@stux
This could be a sign of ageing,
Whiskers normally white when they are born but eventually they can also turn grey or black.
Little Georgy is becoming old Georgy 🙃
@mur2501 Hihi I hope not for him😂 He’a almost 2 years old now 
as far as I can remember this particular whisker was always black 
@stux
It could have been black from birth, anyway Georgy is an exceptional kitty 
Washy also has blackey whickeys? 
@mur2501 It is
All are white with one black one indeed