Enter this formula in the "Conditional Formatting"
=MOD(A1,2)=1 (Odd) 1st Condition Green
=MOD(A1,2)=0 (Even) 2nd Condition Blue
Cell A1 would be Position 1
Use the Format Painter (Paint Brush Icon) on the Menu Bar to format all your positons or cells that you would like to format as Odd /Even