Amazon.com : Selens 15.8x19.7in Pack of 3 Transparent Color Correction Lighting Gel Filter Plastic Sheet in 3 Colors for Photo Studio Strobe Flashlight (Red, Green,Blue) : Electronics
Amazon.com: Eagle Beam Endurance Flashlight Color Lens Filter Set - Red Green Blue Hunting Fishing Military Pilot Nightvision Night Vision Map Reading Tactical Animal Invisibility Boating Blood Trailing LED Cree : Sports
Colour filters
Colour Filters Basic Use for Black and White Film Photography - Tahusa
Four-piece 1.25" red/green/blue/IR filter set for CCD imaging | Astronomics.com
Colour - Key Stage Wiki
Color Filter Paddles, Color Mixing: Educational Innovations, Inc.