Why do commercial painters wear white when they paint?

This site may be of use...

http://www.charmville.com/painters.html

Basically - no-one seems sure!  Although the page does offer some
suggestions.  I'd have to go for the fact it's easy to clean white
uniforms - you can just bleach them.

Don't know if this is the answer but many moons ago when the world was
young and long haired humanoids roamed the earth I read that a man
complimented the painter he had just hired on his excellent skills as
a painter. To this the painter says "thank you sir, but how can you
compliment my work if I have not even begun?" the man says "I've
noticed that you are wearing brand new shoes, only a man that knows
and has confidence on his skills as a painter would do that."

I would imagine they wear white overalls for the same reason. ...

True story: my husband is a painter and like *all* painters, he wears
white; electricians always wear dark blue, carpenters wear light
brown. Once, he got given a pair of maroon coloured overalls. They
were very smart and looked great. He went into the hardware shop one
morning to buy materials and took his place in the queue with all the
other tradies in various shades of brown, blue and white. One guy
turned around to him and says, "okay, I give up. What the hell do you
do?!"
So, the real world answer to your question is that commercial painters
wear white because it's their uniform. If they don't wear white, they
don't know what they are!

I love all these fun answeres.

It is more or less just because that's what's expected.  Why I found
them great, you can see if the paint splaters or it some how gets on
you so you don't sit in your truck on elsewhere with wet paint still
on your uniform.

Another reason - Proffesional painters are rarely called in to paint a
room white.  Primer however is and a new apprentice gets paint all
over themselves.  They typicaly get the primer detail, an hence can
get it all overthemselves and no one will know.