Hi, it took me sometime to find this as well:
Custom menu settings , second tab, AE Microadjustment, see manual page ~329.
After you have set it, it will be confirmed in the "info settings" on the lcd, so press the info several times until you look at the window that starts with WB shift,
Then look at
third row down is says AE +/_ "value you have set it at"
Hope this helps