I realize I’m bumping a rather old post, but I’ve found a similar problem in tutorial 4.
The line:
mat.setColor("Color", ColorRGBA.Blue);
Should be:
mat.setColor("m_Color", ColorRGBA.Blue);
It is a pretty trivial error, but since I’m not very familiar with the engine at this point, it took me a few minutes to realize what the problem was. If I come across anything else while I review the tutorials, I’ll make note of it here.