colormaps. how do they work?

I am trying to assign colours to an n*m matrix N, so I can then display the matrix with red and blue squares with a white background. I've used my code to do this exact thing with a grayscale plot, with black and white squares, but it appears that trying to convert to colour is a lot more complicated than I imagined.

Answer 1

[Elad]

http://www.mathworks.com/help/matlab/ref/colormap.html