why does painters ware white.

Traditionally, most paint used by house painters was some shade of white. The wearing of white is simply because it does not contrast and show the paint drops and splatters that are part of the day's work. Blue Jean painters look pretty sloppy after a few days of painting and are less likely to be hired.

I'm not sure that in the past tense of the adverb that painters do always wear white. As to the ware that they use in the pursuit of their work, those items come in all kinds of colors. So far as their coveralls are concerned, I think that the reason that white coveralls are so often seen is because white is the color that such garments are made in. Personally, I have seen painters wearing what ever happens to be at hand that they do not mind getting paint spilled, or dripped on it.
Let me help you out a little bit to avoid comments as have been thus far posted, if you are concerned with how you appear to others. It is possible that such will be important to you one day. "painters wear white?". Ware, is used to describe articles, such as furniture, or house hold goods, sports equipment or other things that you find in stores for sale. "why does painters ware white", The word 'does' is past tense for the word 'do', which would be proper for the structure that you used. Again, "ware" should be "wear". People that you may one day be writing a resume' for are going to look at your spelling, as well as your capabilities. They'll never get to your qualifications if they see bad spelling and grammar, because the round file is where your resume' will land.

cuz they kain't ware orange.