Ask for help help help help help~~~
So a confusion maxtrix is a 2D array with numbers. Colours are either 0-255 or 0-255,0-255,0-255
So you could find the largest number in the matrix and take each number * 255 / largest and that would give you a gray (grey) scale. You could do rainbow blue, green yellow 0,0,255 0,255,0 and 255,255,0 and replace 255 with the x255/large. Before you have a technical solution try drawing it with crayons. You could just pick one colour (color) 0,0,255 and have shades of blue.