Hi Mark and anyone else that is interested in this kind of thing. I have taken some pictures of my German and Italian tanks side by side as well as adding a couple of British tanks for comparison as well.
I used Humbrol paints on all of these tanks so the colors that I list are that brand. I can't say that the colors are exact matches but I do believe they are reasonable. The truth is that I have seen other peoples vehicles for gaming as well as display models and even museums and there does seem to be some fair amount of variation.
1. Italian M-13/40. I used Humbrol #94 Brown Yellow maybe with a touch of #34 Matte White for scale and sun bleaching.
2. Panzer IIIJ (Kurz) I used Humbrol #93 Desert Yellow and added a touch of #34 Matte White for scale and sun bleaching. I used to use #63 which originally was advertised as Afrika Korps Sand but that color changed to a much more orange looking color a number of years ago. This is, I think, a reasonable approximation of RAL 8000 which was the earlier and darker Afrika Korps Sand.
3. Panzer IIIJ (Lang) This is painted in a mix of 3 parts Humbrol #94 Brown Yellow, 1 part Humbrol #61 Flesh, and #34 Matte White to lighten it. The formula was from Mike Starmer, I believe, who had a bunch of other colors matched or mixed using Humbrol colors.
4. Crusader II and Grant. These are painted in Humbrol #103 Matte Cream with some #34 Matte White added to lighten it a bit. The recommended color was #74 Linen if I remember right. I thought that color a bit too yellow but there definitely is a yellow cast to the British sand color.
Here are the pictures so you can see for yourself.
This shows the M13/40 and the 2 German Panzer IIIs.
Another view from the rear showing the same 3 tanks.
Here is a picture showing the Crusader II and Grant with the other 3 tanks.
Here is a frontal view of the same 5 tanks.
Here is one more view showing the group with the British tanks in the foreground.
Some of the differences are subtle but they are there.