I've had that with the pyropa shawl for months now. I just couldn't get into the groove of it so I finally just ripped it out and started new. I'm still using the Sweet Georgia gradient kit in honey fig just with a few tweaks.
and voila! one semi used skein of now defunct shibui sock (ohhh i miss you shibui sock your colours were awesome) in I think the honey colourway.
and one full size skein of plain white in malabrigo sock arranged in a vaguely gradient fashion.
My only complaint is that you have to figure out where colours 1-6 will actually end up on the shawl. FYI the biggest center stripe is colour 6, usually the brightest of your 6
It is a surprisingly easy knit though, So much so that I'm thinking of having at as the August KAL if it weren't for the fact that it is a pay pattern.
if you're interested in what some other people have done with their palette choices check it out here at The Joker and the Thief shawl on Ravelry.com