Ahhh - yes - thats a red Xantia allright.
Must say I prefer them in dark racing green - envy green
Seriuosly :
In engine bay - car's LH side - near the strut tower - you should find a 3 (capital) letter code stencilled. Sometimes the 3 capital letters are followed by 2 minor letters. The code may be hidden under any ducting, cable bundles, air filter hosuing etc. etc
The complete code has a size approx half the size a pack of cigarettes - easy to recognise.
The complete code identifies exactly what colour/shade/variant the paint is. Your local paint dealer will have a catalogue with all codes listed - and a matching setup code for his auto paint mixer.
PS : some later models have the paint code as well on the vehicle identifier plate - or on a separate plate on the front cross member.