I have seen a number of water spouts, and they were all white to grey.
Never seen a tornado, though.
Dust devils may suck up whatever loose material they pass over (dirt,
grass, etc), and may be invisible if there is nothing to pick up. Once
I saw one that picked up & shredded a wagon load of newspapers that a
paperboy had left in a parking lot (while delivering down a side
street). It scattered the pieces all over the neighborhood.

David Johnson