OK
After examining the Model Air brochure for a while I think they made an error. They say # 54 should be Graugrun which is Grey-Green. But when looking at the color chart it shows # 54 is Dark Grey Blue while number 55 which is next is listed as Grey-Green. I have number 52 which is German Grey on my Tamiya
SdKfz 222 right now and it does not look Grey Violet to me.
So to make a long story short I would go with:
Model Air #54 for your Gruaviolett
Model Air #55 for your Gruagrun
Model Air #46 for your Lichtblau (This one seems right to me.)
All of this advice is with the caveat that the best way to figure this out is buy the different colors and try them. It isn't cheap but anything you don't use you probably will later.
Hope this helps......
Scott