You would have to do as many separate dye baths as you wanted colors. That would require masking off areas already dyed and to be dyed every time you dye another color. I'm not sure you could effectively do this at all with the textured FRN.
Lacrosse players use hot glue to mask off areas when they dye their sticks but that's a larger, smooth surface. In theory, I guess you could use blobs of hot glue to mask areas off, but in real life doing an E4 or D4 scale would be a PITA and it's hard to envision it working very well. But, hey, give it a try and show us the pix!
FIMS wrote:Im assuming if you used the greens and browns and blacks and sort of swirled the dye, it could work, but you would have your work cut out for you.
Unfortunately, you'd get mud brown or black. You need to ^^^ mask the material if you're going to use dye(s).