Andy is pretty much on point with everything he's said so far. I started off using Terminal Fettlers list and then tweaked things as we learned more about the colors. I mostly use humbrols but i have a bunch of floquils and Model Masters paints as well. Since ive pretty much stopped painting for the most part now, i dont look as hard as i used to, but I would search for the floquils on e-bay and usually try and snag the colors we use as i can because i tended to like the floquils better..because, well, they flow better haha. I think they have a higher pigment load with a thinner solvent. The humbrols need to be thinned. I use a combination of Humbrols, Floquil, Model Masters and Tamayia. I also try and match the floquil colors with custom mixes of the other brands because i know eventually some colors will just be gone. Reefer yellow is a good example of one (i use that for the base color for the shoulders and knees) but its getting to the point where i just cant find it in enamel anymore. i have 1 bottle left at this point lol. You can use humbrol 154, but that color seems a bit more "soft" or creamy"... if that makes any sense, lol compared to the vibrancy of the Floquil Reefer Yellow. But its very close and with weathering its hard to tell the difference.
Testors bought Floquil/Polyscale sometime around 2011 or 2012 i think..im a bit hazy on the exact timing..but i do know in 2013 they decided to discontinue the lines and mesh some of the colors into their Model masters line. The problem is the names werent always kept the same, so its like starting all over again searching for colors.
There are some shots of helmets being painted and you can see the floquil and pollyscale bottles. There is no way to be 100% sure if it was enamels or acrylics being used. But my guess is enamels as i recall seeing thinners on the table in some shots. i'll try and find some of the pics im speaking of.
I like using enamels as i fell the final result is a more matt finish where it seems the acrylics tend to be a little too satiny for my taste. Im sure there must be a claercot acrylic that can remedy that, but i always liked the enamels better, so thats what i used.