In my view these are the best colours:
- Black
- Odouro

Grey
- Le mans blue
- Green
- Citrin Beige
- Red (like my carlsson)
Advisory for each:
Black - needs to be washed every three days to keep it looking acceptible. Similar for the blue and the green.
Odouro (?) grey - Nice colour for general useage, difficult to get a grey show-stopper as the grey never really shines like the other colours - flat colours are great for this. Grey hides dirt and scratches much better than anything else - this is a lifestyle choice. General day to day appearance is great. i.e. a dirty grey is much better than a dirty black.
Le Mans Blue - A great colour but does need to be kept clean. The cleaner the better.
Green - Quite rare and very good with beige leather. Green seems to come with cross-spoke alloys and 5-door shell (around here) - although I have seen some coupe's in that colour. Probably not as good for a massive shine session like red, black or blue.
Red - striking - must have airflow bodykit as the grey bumpers don't go so well with the red bodywork. Red paint fades more eaisly than other colours.
Citrin beige - this is a very rare colour. I've only seen 1 classic 900 in this colour and it looked great. It looks a bit like cream but when the light catches it in the right way it seems to change and look darker.