Green side up

A painting contractor was speaking with a woman about her job.

In the first room she said she would like a pale blue. The
contractor wrote this down and went to the window, opened it,
and yelled out "GREEN SIDE UP! "In the second room she told the
painter she would like it painted in a soft yellow. He wrote
this on his pad, walked to the window, opened it, and yelled
"GREEN SIDE UP!" The lady was somewhat curious but she said
nothing.

In the third room she said she would like it painted a warm
rose color. The painter wrote this down, walked to the window,
opened it and yelled "GREEN SIDE UP!"

The lady then asked him, "Why do you keep yelling 'green side
up'?"

"I'm sorry," came the reply. "But I have a crew of blondes
laying sod across the street."