As the title says, I would like to change the fletching color on some of my GT-carbons. the are white-barred turkey feather from true-flight (I think). Is it possible to dip the fletching in some sort of dye while still on the shaft? Yeah, I know I should have bought the arrows in the right color to begin with, but white-barred seemed like a good idea at the time...

I'd try dipping in dye. It'll stain the shaft as well but at worst it will make the feathers release from the shaft.

paint them red!   :D

I would think you might have some success colouring them with permanent ink pens

DDave

follow these instructions, but I would fill a shallow baking dish or something with the dye. Fill the container so you can place your arrow shaft on the rim of the baking dish with the feather pointed down into the dye. Fill so the dye level is just lower than the shaft so you don't dye your shaft. Put however many shafts you can on there and then rotate them after a couple minutes to dye the second feather and so on.

https://www.ritstudio.com/techniques/materials/feathers/

I brighten up my chartreuse feathers that have faded with bright yellow highlight markers.