color wheel in gimp method?

[denzjos]

1/ draw a circle
2/ on gimp menu : Select / To Path
3/ draw a straight vertical line  (lenght diameter circle)
4/ select the line (Fuzzy Select tool)
5/ on gimp menu : Edit / copy
6/ on gimp menu : Select / None
7/ on gimp menu : Edit / Brush strokes on path (value 9 in your case)
8/ clean up the rays
9/ color the sections ( fuzzy select section/ fill section with color 'Bucket Fill Tool') 

PS : Brush strokes on path is a plugin from Ofnuts