Suspect it's a railway modeller's trick on signal colours
.
Page 175 of the
Ateca electrical systems manual shows fours wires going into the door ambient LED which looks a bit like the boot one. A small unit. Presume the four wires are ground and one for each primary colour. Don't know how much mileage there is playing about with that unit. Probably get one primary colour to work or have or a rewiring session.
The foot well light was quite expensive about £15 from memory. Suspect the ambient light is
expensive. I'd assumed some tube alignment but no just a similar small unit similar to the boot one which is also used in the foot well from my previous research. Uses fibre optics to give the strip look.
Part number
VAG 575 947 355 B
About the same price as the standard white one.
Basically the side ambients are put in to make it pretty, the foot well and console base to be practical to pick up things dropped or put down.
No toffee foils or modelling paint required but engineering. Part number from here
https://nemigaparts.com/cat_spares/etka/seat/at/893/947100/
Number 1.
There are C and B types not sure of the difference C (C for colour, B standard?). Here's a C, got the four wires as per the
Ateca workshop manual.
https://www.oemvwshop.com/575947355C-lamp-for-ambience-lighting-p1437972/
Just need a box to control it....