Re:
Darker vs. more silver titanium:
It's all up to how the material is prepared. For example, many bikes are made from Ancotek DB 3.25 titanium - Holland and Ibis among them. If you look at the finish of the Ibis though, if you didn't know you would swear it was made out of different material than Holland, whose finish is much warmer/more silver-ish/"Merlin like" due to the series of Scotch Bright sandings it takes. The Ibis is darker and has no sanding marks.
I am not certain about this, but I believe that Ibis's finish is totally unfinished. But of all modern frames, the Ibis is closest to the Teledyne.
Remember, the Teledyne's were 100% ti, as opposed to an alloy and undoubtably those other metals have an effect in the color of the finished product. Haynes tubing, used by Merlin and Seven, has a distinctive warmth that cannot be easily duplicated exactly with other manufacturers, but some come real real close (Ancotek among these). Holland's 6/4 buikes use Valley Metals tubes and that has yet another hue to it.