And what about Astral Form, Druid of the Flame form, Owlcat form, or Sentinel form?
I'm not seeing anything that would disallow Blizzard from allowing Tinkers to customize or even personalize their mechs. In fact, I think it would be a very cool feature. Like imagine if you could "spray paint" images on your mech, or spray paint it a certain color?But back on the tinker: again, it's unlikely that it'll be done as baseline for the tinker, especially when it's something that everyone would like to have for their class' alternate forms (DH's meta form, Druid's shapeshift forms, Shaman's ascendance, etc).
And before you say its unlikely, keep in mind that Druids can change the color of their forms by merely getting a haircut.
Guilty as charged.