Find the rule specified in the image below.
Taken from Caterpillar Logic, now the app is gone.
I think I found the rule.
There must be exactly one green tile per row, and there must be more tiles to the left of the green than to the right.
If same color blocks comes side-by side, its allowed only once per line. Multiple times of same color blocks placing side-by-side in same line is not valid.