Hi,


I couldn't figure out this! When you push down the sink it it's place on the countertop, the surface material of the countertop, for example black marble, becomes visible on the upper surface of the sink. So let's assume that the sink is steel, metallic grey, having black marble covering the sink spaces. 

What can I do to clean that covers and see the inside form of the sink. (Sink or another material, I have added a graphic to explain better)

Sincerely,
Raif Guven