Was looking at some VR6 mk'3 and love how the side trim is colour coded! Did they come like this or is this modded?

Any tips for achieving this look? Could I just paint my trim or will it not look anywhere near like that? :embarassed:
Also wanting to smooth my front bumper just the number plate section, what filling should I use? Ordinary body panel filler do the trick or will that make a mess?
Where can I replace my numberplate on the front of the car so it's still legal and can I have a square number plate on the front?
Cheers guys