This sweater was knit using 7 hanks (one in each color) of Donegal Tweed left over from the kit for another sweater.
Sequence & color (from the bottom up; color numbers may have been discontinued or numbers changed): Dark Green (0894), Gold (0802), Rust (0880), Bright Green (0803), Dark Red (0840), Tan (0801), Orange (0893?).
Inspired by "Fibonacci," Alexandra Virgiel's design for Magknits, I made up my own pattern using a couple of sources, a "swatch," and an Excel spreadsheet to work out colors. There was a sequence of 5 "rows to knit" (2 rows, 2 rows, 4 rows, 6 rows, 10 rows) through which the 7 colors were rotated, always in the same order. I completely played around with the button band and collar -- and had toyed with alternatives such as frogs, clasps, attached I-cord -- and then totally lucked out in finding the perfect buttons.
I adore this sweater and will definitely make another -- a little narrower next time, perhaps a little longer, maybe trying to carry colors rather than having to weave in a gazillion ends.