The only constraint you have is that you must paint the joints. Since traditional didg designs often feature bands or sections of color, this should be no problem. People are always quite surprised when I tell them my gourdgies are made of pieces glued together. Prime the wood dough surfaces first, of course. Consult didg sites on the internet for inspiration.
Gourds take exceptionally well to wood burning and leather dyes.
If you want a lot of color, an extremely fun and easy method is to use Crayola markers. Finish with an acrylic finish. Or spray the first coat and brush subsequent coats. Add a wax mouthpiece according to instructions that may be found elsewhere on the internet. Congratulations and welcome to the amazing world of gourds.