Madder-dyed leather

To give you an example of what results a period leather dye might produce, a recent thread at RAT alerted me of several items Martin Moser made and dyed with genuine madder.

Vindolanda Calceus
Drawstring Bag

As you can see, it's a bit rusty rather than pure, deep red.  The leather is alum-tawed so presumably it would have been a light color to begin with.  Possibly leather that starts off brown, like a fat-cured hide that's been heavily smoked, will produce a somewhat deeper (albeit brownish) color.