Painting your quartz would be a sad idea.

You are just talking about painting the formica as a backsplash aren't you?

I don't want to paint my quartz counter top. Just the formica above it.

Apologies- I thought you were referring to the Blue Sahara as Formica, but now understand it to be the mottled area above that we are considering. Without knowing where you are headed with the kitchen, I think it only safe to suggest making both areas the same colour, however that can be best achieved - I would like to suggest painting both to give the entire wall a better colour choice, but understand that the colour selections and available products for covering Formica are more limited, and could make that option difficult.