For FE7, the corresponding locations to change are:
0x02D596 light snow
0x02D89D heavy snow
0xB961FF and 0xB96207 rain
0x02DBDE BBQ
0x02D76D sandstorm
0x02DD5D clouds
They follow the same scheme as above, with higher numbers having higher priority.
The only difference is that FE7 uses two numbers for rain, so be sure to change both if you want all of the drops behind the GUI.