As i promised, i want to show my research about the standard camouflage on the late war 251's. I studied a lot of archive pics from 1945 about 251s and found an interesting thing. Some of them had similar camo schemes, specially notes by the yellow patch ont he sides and the front. The camo-map based on the 251/21 Drilling with full of russians in Torgau, April 1945 (Panzerwrecks X and a videostream). The unidentified patches are from other halftrucks which has the very similar camo as you can see on the assorted photos below. Some things were clear up: green base, not hard edge just very smooth border of the camo, 90% the germans used this scheme on late engine decked vehicle, not 100% same camo on the 251s.
Here is the camo-map painted by me, please note that the black line around the patches means the soft edge painting.
(Photos from Panzerwreck series, T.Jakl:Kvéten 1945, and from Internet.)