It does say on that screen a requirement is to have the ambient colour function which I read to mean coloured ambient lighting. That is
Ateca build code QQ9.
QQ9 VWGROUPLCP Interior ambient lighting, type 2
Type 1 is the non variable colour ambient light unit.
You need to check your build codes to see whether you have type 2.
If you have that type 2 unit it's not unheard of for the some of the built in apps not working. These apps will have been programmed from user identified mods. So that's a Google to find them. I must admit I've never had the urge to change from blue which I set mine too from the default palette in the car. Pretty sure you would have the type 2... just just want to change you pallet.
Google
I see on the Obdeleven you also have some adaptions listed under central electrics. See attached. You might not need long coding if it's been brought out as an adaption defined by the menu settings:
View attachment 20253
Suggest you look at that in relation to what Google's throw up. Ambient light colour list sounds interesting. I'm off line so can't look at it, dongle not in. So whatever you find on the subject it can probably be adjusted on the ambient key word list, but be careful!.