Check boxes, and Conditional Formatting

I'm stuck, can someone provide the "How to" for this ?

Setup:

I have 3-cells merged; being A1,B1, and C1.

I have put two (2) "Check Boxes" from the 'forms' menu inside these merged cells(and hopefully on the foreground), with one CheckBox on the left, and the other on the right. The Check Boxes are to represent "YES" or "NO".

ISSUE:

I would like the fill-color of the merged cells to be 'red' if NEITHER box is checked, OR, if BOTH are checked. Lastly, if ONLY ONE box is check, the merged cell fill color is to be green.

Lastly, I do NOT want to see the 'text' status of the check box as TRUE or FALSE.

NOTE: I am hoping that this can be accomplished without the need for a macro.

Thanks in advance to all you smart people :-)

Jay in Calif