The fiber one chooses to work up any project is a multi-faceted decision - do I buy new, stash-bust, use beads (and if so, do the beads determine the color choice) are just some of the factors involved. For my personal Springtime Decadence Shawl, I went to stash to fashion my own gradient. My initial choices are on the right (with George Bailey photobomb, sort of). 
My goal was to work from light to dark, and to the left are the first three colors next to each other. As you can see, those two purples side by side don't have much distinction, and in fact the bottom purple actually brings out the gray in the middle purple. Not the best way to build a gradient, so I injected a deeper purple in between (photo to the right). See, now, how those two original purples pop so much more?
I then worked the first two colorways (Neighborhood Fiber Co. Penthouse Silk in Victorian Village and Louisa Harding Merletto), and then worked just one row of the pattern in the deeper purple (which is Noro Lily Yarn in colorway no. 18 - all three from deep stash). Here is what that looked like:
I may have changed up the traditional gradient color flow just a little bit, but the colors together now work so much better.
These photos were taken on the fly with my cell phone, but you'll see once I have better shots of the finished shawl that these colors look good together, with a little rearranging.
Colors and context are intricately linked.
Do feel free to join us over in my Ravelry group and make a shawl ... with whatever colors work for you.
