Not sure how rare brown oil tan is. Believe that's a question best answered by leather producer or Viberg.
The Echo boot #1 is cool but not something you can wear everyday. White leather boots are along the same line as white denim, which is no no for any fashionable Alpha Male.
I mentioned this earlier...David Beckham is the best dressed male on the planet. That guy only will wear a brown boot every where. Most of the time he's wearing a brown work style boot. You will never see Beckham in a white boot or white denim. Google it