dukel gelb was the standard colour issued in field and applied in factories!
so i'd go with that rather than sand gelb,however green and red browns were often often issued in the field in the form of a thick paste to be thinned with petrol or gasoline
so the colours ranged from almost olive drab to light pea green and a chocolate brown to a ginger colour
often the camo patterns were alos applied by the crews and were applied randomly so the fun in mid to late german armour modelling is play with it practise on a scrap model or paper first ,do you have "panzer modelling masterclass" by tony greenland? if not i can e-mail you some pictures if you like >? its very informative and shows the wierd and sometimes whacky patterns employed!
K