When I was crocheting hats for the craft shows that were in November, I was getting down to several skeins of solid color worsted weight yarn and some balls of sock yarn in my stash. I noticed that the colors of the yarn were either contrasting or at least compatible.
In the photo, there is a skein of medium blue and a skein of light blue. There is also a ball of sock yarn that has blue, light blue, white, and purple. For each hat, I held the strand of solid color and the strand of sock yarn together and crocheted them at the same time. The results were very nice. The hat with the medium blue doesn't have the sock yarn at the brim resulting in it having a solid-colored brim. The hat with the light blue has both yarns throughout.
I really enjoyed this process of making a solid color yarn to have a bit of extra color with it.