[Q] Screen brighter ?

Hello everybody

I have an Archos 45 Helium 4G which is a copy of the K-Touch Touch 2. Some users ported CyanogenMod 11 from the Ktouch to my Archos and it works very well
3 ROMS are available: FIUI 2.3, CM11 and Mokee OS
On FIUI, the screen is a lot brighter than the others ROM, my question is: what system files does FIUI change ?

Thanks