Landscape Dark after making it low-poly

So,i am working on a game right now and i wanted to make the Ground a bit more Low-poly like.
I found out how to do it(Normalized would go into Normal so i did not forget that):

However here are 2 Photos of the Map one without Low Poly and One with Low Poly

As you see,the one with Low-Poly is a lot darker than the normal one.
I used Landscape Tool to make the Landscape. Am i stupid ? xD I havent found any solutions yet.