Now if I could only find a supplier of colored plastic with anti-glare coating...


Since you already have the antiglare coated plastic from HD, you could try lighting gels that are used in theaters and music venues. These are very thin plastic or cellulose filters that come in a bewildering array of colors - they are usually used in front of rather bright lights, so you probably want to start with the lighter shades! Once you have found the shade you want, just tack it to the back of your plastic with some suitable glue. The quantity you'll need is negligable so it shouldn't cost much at all.

Try your yellow pages for suppliers. ("theatrical equipment and suppliers" works in mine)