I have no glue how to change the desktop icon text color. In previous KDE releases it used to be in 'right click on desktop' -> 'desktop settings' but where can I do it now?
It is in the 'Advanced Background Settings' dialog.
Right-click on desktop, and select 'Configure Desktop' (as before). Click the 'Advanced Options' button on the right. There's a place to select text color for the background icon text in that dialog.