If you search Airliners.net ( Hey, I'm not proud !! ) for F-GHNS, F-GPYN, F-GPYC and F-OHQL you'll find that they are all white with just the reg showing. Not quite your criteria but it may help. Airliners.net photo ID 1046667 shows one of those four head on with no reg. showing.
The above came about after searching the first 20 pages of ATR 42 500's. There are a lot more than that !!
If it 'ain't broken........ Don't try to mend it !