Well, I wouldn't ride in wellies, because I've always been told not to. However I am not opposed to riding in combats with half chaps if I have gone to the yard not planning on riding! It makes my trousers look like those blousey old style breeches because they all puff up above the chaps! Muddy khaki bootcut cords have also been witnessed!
I dont like riding in wellies but mine are proper steel toe jobbies, have been known on a busy day to hack out in *red tractor boy* overalls and wellies? I am pikey, or is that so scruffy I might be considered eccentric? Would never go out on an unbrushed horse though!