I got the grass essentials pack, and followed the tutorial, but every time I put the grass in as the tutorial shows, it is a grey color and does not change. I also cannot change the density, it seems like there is very little grass there that is all grey. Am I missing some button or something from the tutorial? The link for the tutorial in question is: http://www.blenderguru.com/tutorials/make-grassy-meadow-scene/
Please let me know if I have something wrong here. I have tried going through the tutorial several times and it continues putting the grass part in as grey. If I just add the grass in to blender by itself, it appears as expected, and multi-green color.

