%vehicle.setNodeColor(<"ALL" or mesh name>, <rgba color>);
examples
%vehicle.setNodeColor("ALL", "1 0 0 1"); will color the entire vehicle red
%vehicle.setNodeColor("Door", "0 0 1 1"); will color just the mesh named "Door" of the vehicle blue. Note: I haven't tested this on vehicles and the jeep is currently all one mesh, so you can't do it to the jeep anyway.