The first picture shows what I did for exercise 1. I used fabric instead of paper simply because I have much more fabric in whatever color you want than paper. By adding a small square on top of the background although the color of the small square is the same on all of them, it will look a bit different depending on what the background color is. And this is not only with the color, but equally so with the size of the little square. Take for instance the dark blue background compared to the light blue background. The squares are the same, but the one on the dark background looks smaller than the one on the light background. This knowledge is extremely useful to have when you are designing.
My second picture for today, is for exercise two. In this case a small grey square was put on top of different colors of background fabrics. Again although the grey fabric is the same on all backgrounds, they all look a bit different. On for instance the orange one, the grey is much bolder than on the purple one. Just as in exercise one, the size looks different depending on the color of the background. But there is also something more. Depending on the color of the background, it looks like the grey has picked up some of that color. For instance the grey on the light orange shows brighter (more orangy) than the grey on the purple one.