Color variation mask

[dhavalmistry]

Is there a way to setup a color variation mask to the populations (specially trees) to give that natural look......

[Mr_Lamppost]

I have wondered about this. I have an idea that a Voronoi 3D cell scalar could be used as a blend function. 

I am assuming that the placement of populations is based on Voronoi cells. 

[bigben]

The first thing you can do is add variation to the foliage across your tree.

http://forums.planetside.co.uk/index.php?topic=1032.msg11455#msg11455
http://forums.planetside.co.uk/index.php?topic=1187.0

Adding variations on a tree level is a bit trickier, although someone else may have an answer there. Adding altitude restrictions works (and possibly slope restrictions?) but that's not entirely helpful if that's not the variation you're after.  It is on my list of things to look at when I get back to working with trees. There may have been some changes in the update that might have impacted on this in a good way... My head's stuck above the clouds at the moment