well that sign comes up if it Has rebooted several times.

try the following first :
power off your phone
open cmd.exe as admin on your PC
cd c:\program files\Nokia\flasher
flasher --set-rd-flags=no-lifeguard-reset --enable-rd-mode


now boot up your phone, change back the clock colour using n9qtweak and disable rd mode by doing:
flasher --disable-rd-mode

even if this doesn't work post here i have a few weapons to beat this instead of simply re-flashing ...