I have done a few sony units and have it on good word the coloured coolant is nothing more than colouring, its the phosphor that does all the colour work and not the coolant.
Think about it, if it was the coolant they would have all 3 red tubes and funny coloured coolant in front and how long would that last?
Anyway, I havent been able to find out EXACTLY what the coolant is except it is primarily monoethelene glycol, as used in radiator coolant, drag car engines, wine making (yes you can drink it) etc.
I have found that they must have put an additive in it as pure monoethelene glycol is a bit thicker and scatters light a little bit more, but in the projectors I have cleaned out this has still even been a great increase.
I have always had to crack open the front chambers and clean them out as most of the fungus has been fixed to the glass and not suspended in the fluid.
Any questions please send me a message or just ask.