What is the meaning for the different color bands around the PICO II 255/266 Series?
The PICO II 256/266 series was originally introduced with color coded bands on the part to denote current rating but has been replaced with the 251/253 series which has the amp rating laser marked on the epoxy. Littelfuse still offers the color coded 256/266 series for those customers that either cannot afford to design in the replacement part or prefer to use the banded product. The attached datasheet explains the color coding system.
PICO II (R) Very Fast-Acting 255/256 Series