To answer your original question first: For painting IDF models you could look at this: https://forums.kitmaker.net/t/modeling-armor-of-operation-iron-swords/34091/62
(I was just the first to answer, do not judge me 
- scroll down a little bit for more suggestions)
On the other hand - let me ask you a different question: are those two colours different?
Now place a finger (or two) over the center line and answer again
