Alan,
Have you thought about "Heat resistant translucent acrylic paints" We hand brush or air brush it onto glass or clear plexi panels for displays,
you can pick up small bottles of different colors at art supply stores or hobby/craft outlets. It's fast drying and light easily passes right through it,
plus you can mix it as thick or thin as you need or like. It will take a little experimenting, -- but mistakes are normally easy to repair or touch up.
Ken
Ver 1.182 on XL Pro plus Ver 1.164 and 1.175 on Windows 7 Ultimate
It Never Fails * Till * You Say It Never Fails