1.) Go to universe sandbox
2.) go to add object, then go to the ring icon
3.) Hover your mouse on ring 2-4 radii and click the pencil icon on the bottom right corner
4.) Set the color mode to manual
5.) Change the Color to Whatever you want!
6.) Click on the object you want to add rings to and click Add Ring
7.) The rings should be what color you picked! If they are not, you probably did not follow the tutorial
Also, If this tutorial did not work, I am sorry!