Luftwaffe and Allied Air Forces Discussion Forum - Ju 88 C-6 Gerhard Böhme NJG 2 4R+HH

Hello, in hope that anyone in this forum can help me, I have me here logged-in today.

I would like to build the Ju 88 C-6 with the identification 4R+HH flown by Oblt. Gerhard Böhme at 1. /NJG 2 and I discovered a profile from this plan in „Luftwaffe Colours “ page 41. In this profile are the bottom surfaces of the cowlings in yellow.
It is in the book written that this marking serves for recognition, but actually the yellow marking is rather well-known from the eastern war scene. Is the bottom surface of the cowlings really yellow and not perhaps RLM 65 (changed engines)? The black white illustration in the book gives me unfortunately no reliable information.

Thanks for your efforts.