MS Project: Calculate risk with formula

Hello Community,

I want to use a custom field that shows me when the end date is less than today (past) or equal to today and the % Completed is less than 100%. I tried the following but it didn't work:

[End]<= Now() And [% Completed]<100%

If the date is less than or equal to today and the % Completed is less than 100%, it should show me a red flag, otherwise is green:

In this example, the 1st, 2nd. and 4th. lines should be green, because it is not 100% completed, but the finish date is greater then today.

The 3rd should be green, because is 100% completed.

The 5th line should be red, because the date is less or equal today and it is not 100% completed.

Can anyone help me?

Thanks a lot!

Joao