CLEAR PURPLE?

Very good suggestions.  I will be out and about this weekend and will explore some of the craft shops.

I have some tamiya clears in my stock pile already so I'll try mixing the clear into the red and blue mix as well. Hopefully I'll get better results.

I went to Michaels Craft last night and found some cellophane wrapping paper in the correct color. If worse comes to worse I'll rig it up inside the nacelle and back it with some reflective silver something.

I remember when modeling use to be so simple.....

I have found two variations of clear paint I am working with on my Polar Lights 1/1000 TOS Enterprise.  At Michael's Village Crafts, in the section for paints to use on glass, there were both a translucent and transparent variation of paints for use to immitate stained and glazed glass.  You can probably find similar stuff at other large craft supply stores.

I got a sampling kit with 6 colors in it, for the translucent, because I want a diffused, not so clear glowing warp engine.  I painted the insides of the warp nacelle domes orange.  There are two domes, one within another, both I painted.  I mounted a tiny light behind the dome to see how the glow would come out.  It worked very well.  I'll take some digital pics and show them in the next day or so.