Thank you for very useful suggestions from Gino ,madmike ,Alexander ,Frenchy and many peoples here. I haven't use its for my last kit but I will try many suggestions such as camouflage and NATO colored scheme with this kit.
For this Challenger ,I use NATO green and NATO black.I added minimal of white to black to tone down it. After completed I found that NATO green is to bright so I over spray overall with thinned black for darken it.
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For next step ,I'm not sure how to do. May be I will use brighter color for make a shading at all surface or may be I will try color modulation. The problem is I never use color modulation with camouflage tank ,is it possible or it's not possible I'm not sure. BTW I will try one and progress in next few days.
Thank you for attends my work ,any suggestion or comments are very appreciate :-)
(Apologize for strange wording and grammatic mistakes, English is not my native language)