Well I'm kinda stumped. Here's what I know about that unit:

I've seen pictures with the DAK Palm in that unit on the glacis and turret bin and on the sides, just in front of the driver's window. The division symbol, which is the funny looking "B" both on the rear turret bin next to the DAK Palm, under the Turret number and behind the Driver and Radio Operator's Windows. The Regiment symbol again on the glacis, turret bin and behind the driver's and radio operator's windows. Usually the Division and Regimental emblems are together.

The DAK Palm when on the glacis is either in the center or on the edge of the glacis on the driver's side. When on the turret bin it's on the left.

21 PD received their Ausf Ls in July-August '42. Shortly after that the unit was transferred from Rommel's DAK to Von Arnim's 5th Panzer Army and shouldn't have had the DAK Palm anymore.

Paint was most likely RAL 8000 with maybe camouflage of RAL 7008. Those were the colors ordered to be used around the time they were built though it's hard from B&W photos to see the camo patterns of those colors.

Sorry I cannot be more exacting, maybe the fellows on Missing-Lynx could pin it down exactly for you. They are way more knowledgeable then I am.