I love dying yarn, really, it is such a fun activity and the results can be amazing.  Last summer I experimented with using just three dye colors - variations on red, blue and green on a luxurious merino/silk base, and this is the result:
This led me on to another experiment a few weeks ago where yarn is repeatedly dipped into a dye pot after being skeined, re-skeined and knotted - effectively this acts as tie dye resist and the dye only settles on some of the yarn.  I tried two sets of three colors and here are the results:
Such yarny loveliness!  This is how the bottom yarn knitted up into a pair of smooshy socks.  For me!
I think I may make a shawl out of the purple yarn, but then again, maybe not!  Decisions, decisions!  It blows my mind how just three dye colors can translate into such a kaleidoscope of when yarn and water mix.