The valve levers on mine are black for the black water tank, and grey for the grey water tank. also have another grey tank in the rear for the galley holding tank. Can you disconnect a small section of the underbelly insulation, and peer in with a flashlight? I would hate to get it wrong, because you always want to empty the black tank first, then grey to rinse it all out.
/SIGPIC]'08 V-lite Flagstaff 30WRLS
'06 Ram 1500 QC hemi
Reese dual cam sway control,
K&N series 77 intake, Hellwig helper spgs. LT tires,
Flowmaster "true duals", 380 h.p., Bilstein shocks