Do the black leather lace slip-ons with a darker heel exist? I see it on the CP site but every store I've seen only carries it with a lighter wood heel. Maybe the lighting in the CP picture is just off.
Those CP website photos are quite deceptive overall, and in the case of those shoes they are very distressed, so I imagine the darker sole/heel is part of that distressing.
It would not be hard to darken the sole.