Unfortunately, we are unable to reproduce this issue in out environment. Could you please examine my test project and let me know if I have missed something. You could also send us more of your code so that we could investigate deeper. thank you in advance.
the Telerik team
Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking system and vote to affect the priority of the items
I found the reason (sorry !). The ItemPrepared event of the RadTreeView was used and the PreparedItem.Foreground property value was set to null (it's an april fool or what ?!?). So, I didn't see my text, it was logical. Sorry for making you waste your time.