The launcher icon overlays such as borders and highlights can be removed quite easily by changing 4 icon overlays in Unity.
1) Make a backup of the following image files in the folder
2) Either make your own transparent images of the same size or download and unzip this file
(from omgubuntu :)
3) replace those 4 files with the same 4 files downloaded from the above link
4) restart unity by pressing Alt+F2 and typing setsid unity (or logging out and in again)
5) if you don't like it then just replace the icons with the backed up icons and restart unity.