In fact, I was able to find a way to contact the United Negro College Fund and wrote to them about the fact that their motto contains a somewhat embarrassing misplaced modifier.
I got a very nice answer back from a woman who works there, a former high school English teacher, who said the UNCF has received many comments over the years about their motto and that they have spent a lot of time and resources discussing whether to change it, but because it is so widely recognized and is even in the Slogan Hall of Fame [who knew?], they have decided not to amend it.
So it stands. I will tilt at other windmills.