Is there a way to set the vertex color by selecting vertex or faces rather than painting? I know there is a way in maya, but I can't seem to find a way to do it in blender.
Yes, you can select vertex while in paint mode. Just switch to the select tool and change selection mode to vertex. Also note that if you select vertex in edit mode and then switch to paint mode, the selection is preserved and edit mode has better ways to make selections than paint mode does.
With your selection just set the colour you want and use the Paint->Set Vertex Colors menu.