OK, Hydrodancer, you owe me $1.47 (the price of the RIT dye)! ;)
It didn't work well at all. At most, they are tinted black. Not even the relatively rough cut marks took the dye well. At least the coloring will be closer to black/gunmetal than white was.
All is not lost, though. At the same time, I dyed one of my daughter's tanktops and she is happy.