The highlite color for the clock background is just a second manila file.
The unpressed clock background in manila 2.52012 is:
31794A12_manila
The higlited background is:
0B6F5C5E_manila
1. extract them using CFC_GUI (a program that can be found over at XDA),
2.save the manila files as a png on you pc,
3.edit them to your hearts content (as long as you remember to keep them the same pixel size)
4. Find out if your rom is cfc_compressed (usually in the rom notes)
5. compress them or dont.
6.Use CFCGui to replace them on your device
7. share
