So this guy walks up to a house and rings the doorbell.  A woman answers the door.

“Ma’am, I’m a painter.  I will paint anything.”

The woman thinks. . . “Why don’t you paint my porch.   Paint it dark brown.” 

So the guy goes to work an a few hours later, he rings the doorbell. 

“Ma’am, I’m all done.  By the way, it wasn’t a Porsche – it was a Mercedes Benz. . . .”