What about natural, uncolored leather?

Yes, that is also an option. The vegetable tanned leather coming from the tannery is a light tawny color. Like some versions of wood, the leather gradually darkens when exposed to light. It also develops a unique patina based on the environment its in and its usage pattern.

There are considerations however. Raw, unfinished (unprotected) leather is highly absorbent so it stains easily. If a drop of liquid hits the leather it soaks in immediately leaving a stain. Even water will leave a reference. Unprotected vegetable tanned leather is very appealing to some people however it is aesthetically vulnerable. Once the stain is set, it has literally recolored the leather in that location and is not correctable.

What can be done is to apply a color coating to the leather covering over stains. However that radically changes the character of the leather from unfinished to a protected or finished state. If this is the condition of your Wassily leather, Advanced Leather Solutions can create a DIY leather recoloring system that with allow you to convert your leather to whatever color you want. This renders a permanent solution that will make your leather appear and wear like new.