Welcome to club Diadema!!! :D
Hope you are happy with the unit, I love mine albeit with L Plates still attached....
Have you considered using those mini neon tubes that Jaycar sell? They are tiny and would fit in that area where you can see all the wiring from underneath.
I have no idea why you wish to light up the group area.. ??? But coming from a car cosmetics background, I think these little babies would suit your purpose.
If not, you can always use led highlighters sold under the Aerpro name. They are 12Volt though...
If you decide to go down the 12v path, PM me as I also have a business selling all these fancy coloured lights etc. for vehicle applications. 8)
I was intending to change the colour of the bezel light for the power switch to blue, just to stop me accidently flicking that switch instead of the brew one....but seem to have naturally overcome that problem :)