So here's what I did ...
First I found a nice hexagon crochet pattern on the internet (here) and decided on the colourways (I did this randomly, no real process here apart from making sure each colour appeared once for each round):
HEXAGON | 1st Round | 2nd Round | 3rd Round | 4th Round |
B | Orange | Green | White | Blue |
Y | Blue | Black | Orange | Yellow |
W | Green | Yellow | Red | White |
O | Red | Blue | Yellow | Orange |
X | Yellow | Red | Green | Black |
G | Black | White | Blue | Green |
R | White | Orange | Black | Red |
Then decided on the size of the blanket and layout for the hexagons and started making.
I'm working with DK wool on a 4mm hook. So far I have all the full hexagons finished. I'll post again when I've decided how I'm going to do the half-hexagons :)