the color chart is based on AK hobby paint,is there alternative color such as Vallejo or tamiya?

it Depends what pattern do you want to paint.Flecktarn trocken-heisse Gebiete a.k.a. desert can be made of XF-57 Buff as base, XF-67 NATO Green and XF-64 Brown. The problem with the grren Flecktarn pattern is the base color. I wold recommend a mixture of XF-5 Green and XF-21 Sky. XF-62 Olive Drab, XF-67 NATO Green, XF-64 Brown and XF-1 Black.
Here some pictures from Bundeswehr homepage.

https://www.bundeswehr.de/portal/a/bwde/start/multimedia/bildergalerien/dienstgrade/!ut/p/z1/hY_NCoMwEITfyI3B32OCLRSsaC215lKCCdZiEwmp9NCHb6TgTbqHgZ3Z_ZYFBldgis9Dz-2gFR9d37LoRpP8nOMU4-wYEUSqXRXQOsUIY7hA82-EuRhtFEFQCwmtY8TbjBhqYMCE9DqtpF3USmUHp73hVhtv0saOS_IyxiXeIKBFfkb9eD3lf5KmJDlNgjA70NMCfPCZv9dd3i1PQ3vnSoyy1B35GdNznxRF2H8Bpy-8JA!!/dz/d5/L2dBISEvZ0FBIS9nQSEh/#Z7_B8LTL2922DM6A0AQEQ4BS92027

Thank's for the advise.
Some question,about the 4 figures odern german tank crews,the two figures wearing darker color.do you know the base color.

I usually start with the XF-5/XF-21 mix. good refereneces about camoflage uniforms can be found here:

http://camopedia.org/index.php?title=Germany