The 80 series of filters are blue. They are used to balance daylight film under artificial, tungsten or standard (household) incandescent lighting.
Filter factor 2 (+1 stop)
Kodak gelatin filters are available in 3 x 3" (75 x 75mm), 4 x 4" (100 x 100mm), 6 x 6 (150 x 150mm) and 14 x 18".
80 Series Color Conversion Chart
80A increases color temperature from 3200-5500 degrees Kelvin (commonly used with 3200K lamps)
80B increases color temperature from 3400-5500 degrees Kelvin (commonly used with photoflood lamps)
80C increases color temperature from 3800-5500 degrees Kelvin (commonly used with flashbulbs)
80D increases color temperature from 4100-5500 degrees Kelvin (commonly used to remove extreme orange or red)