It should be possible to make a shields down emissions/visual cloak using an inverted shield technology. Since a shield uses some variety of monopolar function to allow passage of energy/matter in one direction, if the shield is pointing inward at the generating vessel, that vessel should be invisible (visualization is a reflection of light from the hull).
This would require that the ship not be generating thrust, and that no active emissions (weapons, active sensors, normal shields, etc) are functioning. You'd have normal shield charge cycle, and, if the ship wants traditional shields, you could only have one or the other active with a charge cycle for activating either.