Conditional Formatting after comparing % differences in two cells for EXCEL 2007

Used Cond formatting successfully in 2002, but changed to 2007 and having trouble understanding formula usage and absolute v relative addressing requirements in the formula(s).

In my worksheet, I add a new column of numbers each week, and compare the numbers in the cells of the two most recent columns. I want to conditionally assign one of 3 shades of green, to the newest number (newest column) in the cell in each row, depending on whether the number in the newest cell is greater than the previous (week's) number by:
1) =>2% and < 4%,
2) =>4% and < 6%,
3) =>6%.

At the same time, I want to assign a shade of red to the number of the newest cell if it is less than the previous (week's) number using the same % ranges if the more recent number is lower than it's row partner from the previous week. In addition, once the formatting is assigned, I want the colors to remain for historical reference.

Thank you for any help and direction in the usage of conditional formatting using a formula(s).

MSWIGZ