using cells as graph

Is there a way to put a number in a cell and shade the same number of cells to the right?
I see this working like the REPT function... but I can't make it color the cells.

A1 B1 B2 B3 B4
4 Red Red Red Red

Sure.

To color horizontal bars, use conditional formatting on colums B to Z or more and use conditional formatting with the formula

=COLUMN()-COLUMN($A1)<=$A1

to color vertical bars use
=ROW()-ROW(A$1)<=A$1

See attached.