A wonderful innovation in the yarn world for knitters who are rather lazy but still want to add color to their projects is self-striping yarn. This is yarn that is dyed in a specific, technical manner to ensure (or at least make it pretty likely) that the color changes will line up more or less in stripes along the knit fabric.
It doesn't always work completely perfectly, of course, but the finished effect is really lovely and gives you gradations of color without any effort.
One great thing about self-striping yarn is that you really want to use it on simple, Stockinette Stitch projects, because they yarn provides enough interest and really works best in that stitch pattern. So you can finish self-striping yarn projects quickly, easily and without a lot of thought (you'll knit quickly, too, because you'll want to see the next stripe appear).

