Bi-Color and Tri-Color LEDs--two colors in one standard 3mm or5mmpackage! How do they work? There's multiple legs on them (withtheexception of our 5mm Flashing BGR)! Our Bi-Color LEDs havethree legs and are common cathode meaning one ofthe legs is thenegative lead and each of the others is a positive lead(one for eachcolor). Our 5mm Tri-Color Full Spectrum LEDs are commonanode meaningone of the legs is the positive lead and each of theothers is anegative lead for one of the colors. We match our chips foruniformlight output. For example, take a 3mm Bi-Color Blue/Red LED. If youwant blueluminescence you'd connect the common negative lead and thepositivelead pertaining to blue to your power source. If you wantredluminescence you'd connect the common negative lead and thepositivelead pertaining to red to your power source. If you want bothcolorsshining then power both negative leads at once!