oh, it might be because I was looking the available colours by our builder's window supplier. are you aware of your window supplier's name and what colours they have?
we have bradnams windows. ultra silver gloss is what we used on our house. i think it will be pretty close to the surfmist. the screen representation of the ultra silver gloss isn't very acurate at all. and i'm pretty sure southern star windows do ultra silver gloss, too.