I wound a ball of the mix-matched yarns by winding a little (say a yard or so) of one color, cut the yarn and tie on one or two yarns from another yarn and wind. Cut off at about a yard and then repeat in random fashion winding a colorful ball.
I did this on my wheel, but you could just as easily taken the four yarns and tie them together and wound a ball. You wouldn’t have the added twist so you would have to watch when winding and using the yarn in a project for knotting.
I chose to weave it on my simple loom with the left over warp yarns from a previous project.