This may only be funny to me, but I am all the time finding myself outside, where people can see me, with paint on my clothes.
It, of course, doesn’t help that most of my clothes have paint on them. But I do get a little weary of explaning it when people ask.
So rather than have everyone assume its dirt why not get a new painting shirt? Over the years you’ll add your own strokes of genius and it comes with a perfectly acceptable explanation for when you can be seen by people, already on it!