If statement using date to change row colour

I have a sheet with the following header row:

Reference Client MAWB / BoL Date logged Date completed Days to resolve Logged by Caller type Error area/ Type Completed by

This is a rough CRM system to try and resolve queries logged by a certain time. Now I need to know how and what formula am I to use if I for example (1) want a row to stay as is if it is blank (no data) so no change in colour; (2) have it change and stay yellow if it is 1 to 2 day after the date logged; (3) change to another colour say green if it is 3-5 days after the date logged and (4) finally turn red if is is > 5 days than the date logged.

Essentially trying to expedite and increase customer relations by resolving queries as soon as possible and by colour coding them in term of time after date logged we can see who does not attend to queries and who is effective and efficient.