Matt Newsome's article on Solid Color kilts states:
Perhaps the most famous nineteenth century figure to sport the solid kilt is Queen Victoria’s own John Brown. He was quite famous for wearing the solid black kilt suit, complete with matching vest and jacket.
The whole article can be found here: http://albanach.org/solid_kilt.htm

Of course this doesn't mean the Queen didn't commission a tartan for him, just that he seems to have usually worn a solid colored kilt. Too bad it wasn't brown (Zing!).
A cursory google search hasn't turned up any proof either way yet. Did anything you were reading cite sources that you could consult for more info on this legend?