I pulled out my Revell kit (latest issue) and the one book I have that has HE 115 (Axis Aircraft of WWII) data.
A closer look at the Revell box top suggests that it is rendered in a dark grey/dark green, not 70/71. The book has a picture of the 115 looking directly down from above as it is prepped for a mission. The colors are somewhat blended together by weathering/fading but it appears that it is a dark grey/dark green combo. The pattern seems to generally follow what is indicated on the Revell paint diagram.
There is a side view of a KuFlGr 406 aircraft with distinctly Grey and dark green camo, but the pattern is differnet from the side views given by Revell. FWIW the Brits had 3 A-2s (previously Norwegian) and 1 B-1 captured from the Luftwaffe, though I have nothing on thier markings. Since they were used for clandestine ops perhaps they retained thier German markings. One was even used by BOAC.
What I found odd was that I had thought I had a ref that said aircraft flown over water were supposed to be 70/71 but the dark grey makes sense after seeing the picture even the lighter grey one seems as if it would blend in well. I haven't the faintest idea what the grey was though RLM66 would be seem reasonable.
They were apparently also used in the Med, I suppose you could look at other Luftwaffe aircraft in the Med and use those colors with the same pattern.
Lotsa luck, Frank