Jay i know what you're talking about, I used a flourescent orange testors paint i had lying around to tint the epoxy, kinda cool because there's a lot of orange underneath and gives it a glowing look.
Nice looking pen! Do you know if your "Lava" blank is the same the "Neon Nights" blank that Ernie at Bear Tooth sells? http://www.beartoothwoods.com/catalog/product_info.php?cPath=22_60&products_id=445
I just made a chrome baron out of Neon Nights blank. I painted the tubes black. It doesn't looks as silver/gray as yours but it also doesn't seems to shimmer as much as yours does.