According to:
http://www.knifenetwork.com/workshop...r_warner.shtml
You should start at 0V and work your way up to the voltage/color you desire. Gray is the natural color of titanium so the voltage is very low according to:
http://www.valhallaarms.com/wyvern/t.../anodizing.htm
The above posts handled the voltage current issue, but starting at 0V and working your way up will definately help too.