Shade a submatrix within a matrix

[hlogoma (Thomas Vermaak)]

I am using the free version of the Wolfram Alpha Mode Notebook. In it I have an 11 x 11 matrix and I would like to shade a sub-matrix, 4 x 4 sub-matrix, within the 11 x 11 matrix.

Could you please point me to an example or some documentation that illustrates how this is done.

Thanks.

[schandler (Seth Chandler)]

If you are willing to wrap your matrix in Grid, you can do something like this:

Grid[RandomInteger[{1, 8}, {11, 11}], 
 Background -> {None, None, {{{4, 7}, {6, 9}} -> LightRed}}]

[hlogoma (Thomas Vermaak)]

Thanks Seth.

[rohitnamjoshi]

You could try applying a Style to the elements

SeedRandom[123];
r = RandomInteger[{1, 8}, {11, 11}];
    
MapAt[Style[#, Red, 16] &, r, {4 ;; 7, 6 ;; 9}] // MatrixForm

[hlogoma (Thomas Vermaak)]

Thanks Rohit … it worked great.