Hello Luiz.
Tank crew during the winter of '44 would have had on the cold weather jacket and bibs. These were produced in a color called Olive Drab #3. You can find color photos of a reproduction
here.
Unfortunately, I have never seen the actual material in person but I have seen a variety of color photos, taken in different lighting, and printed in different publications and to my eye, the color of these items always looks slightly more brownish-yellow than it does green. With that in mind, I tried to represent a slightly yellower version on my models. I cannot say how accurate it is but I was pleased with the results. Others here may be better able to tell you the "correct" paint shades to use for a more accurate representation of OD #3, but here is the list of the Vallejo colors I used on my crew:
JACKET
Base color = #912 Tan Yellow + #983 Flat Earth
1st Highlights = Base color + Tan Yellow
2nd Highlights = Tan Yellow + #819 Iraqi Sand
1st Shadow = Base color + Flat Earth
2nd Shadow = 1st Shadow + Flat Earth.
Collar, waistband and cuffs = Flat Earth; add #918 Ivory for highlights.
Zipper = #998 Bronze + Citadel Boltgun Metal
BIB PANTS
Base color = #912 Tan Yellow + #983 Flat Earth + #72050 Cold Grey
1st Highlights = Base color + Tan Yellow
2nd Highlights = Tan Yellow + #819 Iraqi Sand + #918 Ivory
1st Shadow = Base color + Flat Earth
2nd Shadow = 1st Shadow + Flat Earth.
Filter = #914 Green Ochre + black ink
Even though the jacket and bib pants are made of the same material, I changed the color slightly on the bibs to indicate different dye lots, different wear and tear, and to make the figure more interesting to look at rather than all one color. You can see the finished figures near the bottom of
this page. It is difficult to see in the photos but the bibs have a slightly more olive tone to them. This is a result of the addition of grey to the base color and a very thin filter of green ochre + black ink.
Hope this is helpful and be sure to post some photos of your finished crew!