First Great Western
First Great Western (FGW) has had three livery variations within it's fleet. Two of these are substantially different, but the third is barely noticeable, but if you want to get it a model right, then it really is worth taking note of.
The first is the original "Fag Packet" livery, and was simply vinyls applyed on top of the old Great Western Ivory Livery. This was a collection of Green and Gold. All but one wore this livery.
The second livery that FGW used, has now been nicknaed "Barbie". This livery is in line with First's Corporate Colours. It was originally white/blue/pink, but this has been replaced with a simpler Blue/Pink/Gold, which is the third livery variation.
But, there is now a fourth variation being applied, and is known as 'Neon'.