A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data
The following conditional formatting formulas can be used to achieve your stated results. The formulas must be in the order shown and each must have the "Stop if True" box checked.
TODAY()-151>=INT(A1) dark red
TODAY()-120>=INT(A1) bright red
TODAY()-90>=INT(A1) orange
TODAY()-61>=INT(A1) bright green
TODAY()-46>=INT(A1) pale green
TODAY()>=INT(A1) white
Replace all references to A1 with the first data cell in your range.
Your specifications were ambiguous for 90 and 120. I removed the ambiguity by including those values in the range where they first appeared.