eg. value 1 and 2 in a cell should make an entire row red

eg. value 3 to 6 in a cell should make an entire row blue

Ideally I want a formula when if I put 1 or 2 into a cell it highlights
the row as red

maybe I if I input a 3, 4, 5, 6 it highlights red

Any thoughts? Thanks in Advance.