You shouldn't include RGB in the formulas, it is not an Excel function. Actually you don't need to use rules of type formula at all.
Select E6:E12
Set the fill color to green. This will be the default.
Click Conditional Formatting > Manage Rules...
Delete the existing rules.
Click New Rule...
Select 'Format only cells that contain'.
Leave the first drop down set to 'Cell Value'.
Select 'greater than' from the second dropdown.
Enter 8 in the box next to it.
Click Format...
Activate the Fill tab.
Select yellow.
Click OK, then click OK again.
Repeat these steps,, but with 9 in the box and red as fill color.
Finally, close the Conditional Formatting Rules Manager by clicking OK.