imagesc replacement so I can see individual values colorcoded

Is there a way to show the binary matrix b as points (say using scatter or a similar command) so I can see individual 1 and 0 values corresponding to different rows and columns with different colors for 0s and 1s similar to imagesc?

For instance the following script generates

a=rand(6,5);
b = a > 0.5;
% b is generated as follows
%   1   1   0   0   0
%   1   0   0   0   1
%   1   1   1   0   1
%   0   1   0   1   0
%   0   1   1   1   1
%   0   0   0   1   0
%replace the following so on the plot 
% corresponding to (i,j) I can see a yellow "x" representing 1  
% or a red "x" representing 0.
imagesc(b);colorbar;

Answer 1

[Sulaymon Eshkabilov]

Hi,

A simple way is:

spy(b)

Answer 2

[Walter Roberson]

imagesc(b);
colormap([1 0 0; 1 1 0]);  %red and yellow
colorbar();