Troubles with directional light on Android

Hi

I'm making 2d platform game in unity. Platforms are made as Cubes from Mesh filter (cube). Colors of platforms are random generated in script.

Everything seems to be working in editor but when I build my apk and install it on phone then all of platforms are magenta colour (which is set as default in script). On the other side if I disable Directional light in editor, then all of the platforms have dark, almost black layer (they are all looking almost the same).

How to solve it? In build I'm using OpenGLES2 as Graphics API, phone is Oneplus One with last version of android.

Thanks for help.