They use Erwin to do a VIN lookup which you can do yourself if you pay the time online or just ask the dealer for a print out of the build code or the paint code. On any new vehicles they know the paint code from the Seat name but those little model cars for the colour have the code on them as well if you turn them over in the dealership.
There was a French Seat site we all use to look at

.
Cupra:
TEINTES répertorie les couleurs de plus de 1100 modèles auto. Comparez et identifiez les couleurs de vos véhicule favoris !
www.teintes.fr
Use to be the place where first time
Ateca buyers went to look at the colours

. The names are there. Then you have a Decca around these links:
They give the paint name to the code. Then if you want to up the fun you look at the Skoda name against the code. It's all the same paint.
The original
Ateca 2017 model the
brochure colour was Samoa Orange. Some people did buy Orange Atecas. Looked fine on a summer's day in a seaside resort but perhaps not elsewhere. You had to be brave enough to carry that one off.
Attached the launch
brochure PDF for interest. They may well have changed the colours since then - see the French link above.... was the go to place as I said for people into the colours. We were buying blind then ordering the car before we saw it.
My memory served me right on the Seat side back in 2016 if you save the PDF of the car you built it told you the paint code

.
I see now for the Cupra it doesn't. I did build a Dark Camouflage one. Hmmm the site for Cupra didn't give the code on the PDF but a Google bring up this. A board Seat / Cupra parts sponsor. Use you registration / Vin:
Genuine Honda parts at discounted prices. Buy online today or call us on 01524 68071. We will never be beaten on price for any genuine Honda car parts.
www.seatmotorparts.co.uk
So there you go.
Quite interesting to track the colours across Seat and Skoda

.
So yes, get the name and use the parts link to get the code. Dealers sell the paint or central parts and I said early if your dealer is some way, cross referencing to Skoda you can get it from there if closer. They order parts in which is cheaper than Skoda mail order that adds the post on. I got the Skoda paint for mine plus the celebrated ice scraper that slots in the fuel cap, just a train ride for me at the time rather than a long treck to a Seat dealer, now 5 minutes where I live. Cupra is 60 miles or so. Reckon any Seat dealer would get the paint in for a Cupra if you like the personal touch. The supply chain will come together outside the brands in the dealership.
Seat Motor Parts being a sponsor off the board a discount applies:
Supplier of official SEAT and CUPRA parts to the community.
www.seatcupra.net
Quite a few options to rustle up the touch up paint
- the dealer parts department who just know or look it up on the VIN
- Seat parts online using reg and Vin, link above
- checking out the little model tests colour plates in the dealership assuming Cupra have these little models stuck to metal plates that you take outside to the daylight to study
- website links to colour charts
- you don't have to stick to Seat / Cupra you can be a devil and buy the same paint from Skoda if the codes match