I have a header row where I want to alternate the shading of every 3 columns within a specific range of columns.
For example,
A1, B1, C1 Shaded
D1, E1, F1 Not Shaded
G1, H1, I1 Shaded
J1, K1, L1 Not Shaded
M1, N1, O1 Shaded
Is there a way to do this WITHOUT having to enter each cell for...