I'm currently using the following as conditions 1 and 2 for a custom format that alternates the shading every other line.

What I can't figure out, is how to add another condition. Basically, I want to check column M for a Y or N value. If Y if present, I want the text to be green. If a N is present, red text.

I can do the Y/N bit just fine, but can't seem to do it at the same time as the alternating shading.

=MOD(SUBTOTAL(3,OFFSET(A$8:A4,0,0)),2)=0
=MOD(SUBTOTAL(3,OFFSET(A$8:A4,0,0)),2)=1