Both Neutron and Proton are great for dyeing. Neutron takes the colour a little faster and more faithfully in my experience. White Neutron and UV blue/clear Proton are pretty much the ideal dyeing plastics, but I've had success on pretty much every mvp disc I've dyed.
Here's a Neutron Anode that got seven colours of Rit and iDye Poly. It always blows my mind how well yellow dye takes.
And, since I'm shamelessly posting my favorite dyes, here is my favorite Proton disc I've dyed (also an Anode).
Like BigSky said, they make blank ones expressly for dyeing/stamping. Stamps come off easy for Neutron plastic (you can see the ghost stamp on that Cyril Sneer), but aren't worth trying to remove from Proton.