Borrowed from "The Southerner"
Not all blonde women are dumb
A blonde woman decides that she is sick and tired of all the blonde jokes and how all blondes are perceived as stupid, so she decides to show her husband that blondes really are smart.
While her husband is off at work, she decides that she is going to paint a couple of rooms in the house. The next day, right after her husband leaves for work, she gets down to the task at hand.
Her husband arrives home at 5:30 and smells the distinctive smell of paint. He walks into the living room and finds his wife lying on the floor in a pool of sweat. He notices that she is wearing a ski jacket and a fur coat at the same time. He goes over and asks her if she is OK. She replies yes. He asks what she is doing. She replies that she wanted to prove to him that not all blonde women are dumb and she wanted to do it by painting the house.
He then asks her why she has a ski jacket over her fur coat. She replies that she was reading the directions on the paint can and they said, "For best results, put on two coats."