I am making a Sierra pen out of Orca Acrylic, white with balck highlights. The gold color of the pen tube shows through the acrylic when done. What is the trick other than go to a darker color...Thanks...MK
Scuff sand and paint your tubes. Make sure that you apply a thin coat if you drill a tight fitting hole, if not move up a bit size to accommodate the paint thickness.
I have used Behlen Solar-Lux Stain on the inside of the blanks with good results. It comes in lots of colors, but I use mostly Jet Black. Got it at Woodcraft, but it's probably available lots of places...