I've noticed that the lotion also contains mild cleaning agents ("It is ideal for the gentle cleaning of smooth leathers"). Is it less harsh than the renovateur? Or could it also strip colour? Most of my bags are black, dark brown or dark blue, so I guess they're a bit more prone to this than lighter coloured bags.
Saphir advised the nappa cream for my bags, although they are grained leather. Someone who collects Delvaux purses told me the Saphir Creme Universelle is also a very good product for the grained leather or box calf.