NO, that is wrong. The White/black wire is hot and when grounded lights the dome light by itself. The violet wires when connected to the white/black wire simply connect the circuit through the doors and include the dome light. That circuit grounds when one of the door switches is opened, creating the ground.
I have exhaustively tested the circuit and promise you the white/black is hot. On SOBills' diagram, he shows that wire as violet. On my 71, it is White/black.