The colours I quoted were for a LGB unit.. Seuthe don't make it quite so easy!
The rated voltage is what it is supposed to be run at, and give a decent life of the unit against the amount of smoke produced.. - Hence talk of running LGB '5V' units at about 6.5V..
Alternative fuels:
Garden lamp oil - with / without Citronella is a good bet..
Baby Oil - Though this produces a sticky-black gunk, over time, so will cause premature failure..
Vaping fluid - Preferably without Mint, or 'fruit' essence, I guess!
As with all these 'fluids', you are vapourising a mix of hydrocarbons.. Go easy on it, if you are indoors, and have some ventilation.
PhilP.