Hi Steven,
Titanium seems unlikely - its a lot of work for a very small weight saving, but then you can squander 100 bucks on the minimal saving of a carbon fibre bottle cage, so who knows. Thing is titanium doesn't have much of the necessary 'spring' in it, does it?.
I have some Gold anodised Galli aluminum clips I bought from Nigel at 'campy oldy ' he has had other colours including blue.... could they have they anodised some grey ones (gray ones in US?) ......maybe to match the grey/gunmetal Campag Groupsets of the time?
Alfredo Marcantonio
Twickenham England