I don't know about the color because I don't do modelling myself (anymore), but
normally my modeler mixed the color himself and painted 3 levels of similar
color (in this case, sand color) but different tones (whiter & whiter). Weathering
comes afterwards. For a Panther in Italian campaign, I think it should be in a
3-color camouflag scheme (Dark Green, Dark Brown and Light Brown). On my
Web site there are several Panthers on show, in several color schemes. Some
are used in dioramas. Here's the list :
http://www.geocities.com/~falconbbs/modelcnt.htm