FWT RED Liquid - Bright Dyes Tracer Dye for water or wastewater leak detectionDescription Color: Bright Dyes FWT Red Red offers greater contrast to heavy concentrations of green algae If the water were yellow Bright Dyes FWT Red would be best Its fluorescent properties offers greater apparent contrast than non fluorescent blue May be used for visual, ultraviolet* and fluorometric* inspections Has a higher light fastness than FLT Yellow Green Resistant to the absorption of suspended matter Type: Liquid Dye Best for moderate to