FWIW, I have a few of these saddles, one in black, one in slate, and one in natural. The slate eventually started to look like the natural, the natural got a bit dingy and started to look like the faded slate, and the black faded so it looks like a new slate. So, if you think you want black or slate, you probably want black.
I used to care about what they looked like, but that went away - they are the perfect saddle for my anatomy and riding style so I'll take them at this point whatever they look like.
-Jeff
Silver Spring, MD