You should be able to see all the patches above as 21 distinct squares from black to white on the top level and in reverse on the bottom level.
adjust your brightness and contrast
If your monitor is set to at least 256 colors you should be able to adjust the brightness and contrast on your monitor so that the greyscale strip above shows as distinct colors. If many of the black boxes are indistinguishable then you need to adjust it so you can see the varying levels of grey to black.