I use Classic Chestnut to wrap guides on the bamboo rods I make and I have a good stash of that color. The difference in dye lots becomes readily apparent when the spools are exposed to sunlight. Even so, the trout don't seem to care.
John, You could also use two different sizes of hen hackle. The rear hackle could be one size smaller than the hook size, the front hackle could be the designated hook size. Tie in the rear hackle, then dub the body halfway up the hook. Wind the hackle forward to where the dubbing stops. Then tie in...
I fish the bamboo rods I've made. Most of them are based on Paul Young's tapers & they are wonderful fishing tools for Wisconsin's Driftless Spring Creeks. I still use the first rod I made, a 7.5' 4-5 wt. Perfectionist, with some regularity.