I can lend you an A8 cluster and wiring to play with if that would help? I am going to be fitting a mk2 RNS-e in to an S8 in the next few months so if you can get the DIS working that would be some very nice icing on the cake
'Hicol' is very likely the colour screen as it was called 'nav high' or 'highline' in some models. I have a B7 with it, and I'm sure that term or something similar appeared in the spec sheet.