I would like to be able to do conditional formatting against other columns and not just the existing conditional formatting.

For example:

Column 1 = 1.2
Column 2 = 1.5

If the value of Column 2 is greater than the value of Column 1, I want the color to be green.
If the value of Column 2 is less than the value of Column 1, I want the color to be red.
If the value of Column 2 is equal to the value of Column 1, I want the color to be black.