I've spent a couple of days lining up the 10 different colourways of Kureyon to choose a relatively natural progression of colour changes, but was running into an issue. I'd been envisioning a colour progression going up from the lower front and gradually changing through related colourways. The "graft in the middle of the back" scenario causes a problem, though. Although I'll get a nice colour progression up the body and to the front neck opening, if I continue with the progression as planned I'll get a "conflict" where the back sleeves are joined to the body.
We came up with a solution. I'll work the body through a colour progression (see above), but as soon as I divide up to work the upper front flat, I'll change the rules. At the changeover point from circular to flat, I'll change to a new colourway. I'll track the colourways I use up to the neck, and then work the same sequence in reverse back down again to the back graft point. For example, assuming it takes two balls to work from middle front to the neck, call them A and B, I'll work B and then A down from the neck to the middle back.