Sorry Philippe, I didn't answer Your before.
When You speaking about rules for painting Russian/Ukrainian vehicles then my answer will be slightly strange but it's true: Army use paints they still have from Soviet Union (remember paints can change their properties when made more than 10 years ago) and what can be done by mixing of paints they have.
Surely rules from Defence Ministry exist, but because of lack of money everything useful is ... in use.
Sincerely, Alexey.
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