How to export heightmap texture right?

I need help on exporting texture right. If you got an idea on how to do this right, hoping that you could help me.

Below is the images exported heightmaps and textures from land, WdArena, but still got a problem loading its texture true color, note that I havent implemented the usaged of tile texture here. (Note: heightmaps is working well)

I extracted the C# code from MisterKid and convert it to Java http://forum.ragezone.com/f456/emulating-recreating-flyff-unity3d-1066468/

https://ibb.co/D5ZdBRH