I haven't actually used the dye yet (though I have plans for some) but I've done a fair bit of reading on people using a fabric dye called Rit-Dye.
I apologize that the link is on a different forum but it's the one I first came across and prompted me to look into.
Rit-Dye Colour for WC Tubing
I love this case and the effect that painting the mesh had. I'm doing mine in red and black and hadn't thought about changing the mesh colour until reading your log. Was there any special steps you needed to do to prep it for painting?