Black?

This cheeky walnut thief visited our garden this morning. It ran around as in a panic, not knowing where to stash her ill gotten gains.
What puzzled me more was the colour of its fur, thinking is it a black squirrel? They do not appear in the wild in Poland. Until just found out that "Red squirrel fur can range from jet black to a dull yellowy-brown (often referred to as “buff”), covering most shades of red and brown in between, and the pelage colour varies according to location, season and age (adults tend to be lighter than juveniles).