Sorry about the poor description.
I have a grid. Now, should I add a layer as I want to fill in in red and black sequential colours, across the entire grid? I used MS Paint to do this, but the issue is the same. I would like the angled diagonal line from bottom, to top, to be straight and not free hand or such, and then fill in that area, with red, and the next with black, and so on. I would then repeat this time the whole grid is covered with stripes alternating red and black, on an angle.
Cheers,
British_eh