fading on reds is down to what type of paint is used, the reason vauxhall reds fade (usually older models) is because at the time they used a 2k solid red rather than a basecoat/clear coat option.
2k solid reds fade as they dont have any UV protection.
the basecoat option is protected by the
clear coat so wont fade.
these days most manafacturers use base/clear piants so you dont see many reds fading as you used to.
if your thinking about painting red ask for your chosen colour in solvent basecoat and then get a good quality clearcoat(lacquer) you wont have any fade issues then.
probably the brightest boldest red is Mazda true red which is on the new MX5's etc.
Ferrari Red wont cost any more to buy in solvemt basecoat than say a Vauxhall red.
hope that clears it up!