I just got oxyotl and was wondering how to paint glass. I was thinking green for the fluid then the empty part would be maybe like a light space wolves grey or some mixture of blue and grey then varnish the whole thing but not sure.
Best product I have seen for reproducing Glass or water for that fact is called Glass Coat it is an Australian product. One coat of this stuff is equal to around 50 coats of varnish check out the web site just google glass coat australia.