Barris - you can do this by creating a shared variable.
For example, create a forumla like so
If shared numbervar X = 1 then
shared numbervar X := 0
else
Shared numbervar X:=1
In the footer's color propery set the following
If shared numbervar X = 0 then
grey
else
white
If you wanted to you wrap both sets of code into the footer's color properties like so - but should set your variable in the report header or somewhere in the begining of the report so you know for sure what the value will be at the start of the report. Not necessary, but that is what I prefer to do.
if shared numbervar X = 1 then
(
shared numbervar X:= 0
grey
)
else
(
shared numbervar X:= 1
white
)
Can't promise the syntax is completely correct, but I think you get the idea.