I believe I found a bug in the NTreeList. When drawing a group node the foreground text color being used from the palette is not the same reference as the one for a non-group node. When using the Longhorn palette, for instance, this shows as a problem. I've attached a picture using a Nevron sample TreeList window circling the differences. Please consider fixing this in a future release. I'm using 11.12.14.12 on Win7. This is likely one line of code for you to fix.
To work around I'm trying to add a renderer so I can draw the group node text myself. I've overridden the paintText method. I've got this working but I can't determine how I can know if the group node is currently "Hot" (i.e, the mouse is hovering on it) so I can use a different foreground color. The paintText method has NTreeNode and NTreeViewExPaintContext parameters. I've been looking around but haven't found the property or method on either which tells me the node is "Hot". Can anyone explain how to know this?