Why is the steering wheel black?

On and off, sometimes I feel that the van's steering wheel is very sticky. Maybe its because of the protective cover or maybe its something else. I should never have found out....

I used those moist clean wipes on the steering. The first wipe was on the
left. The steering wheel made the whole wipe changed to black. On the
right is the third wipe, which looks a bit smudged. Imagine the amount
of dirt and grime on the wheel. Yucks

Nothing to see here, move along, Move along!

Casualties of war on the fight with termites