As explained by Arduino to Go, each color band on the resistor corresponds to a number but this can differ depending on the band's placement.It's not complicated, but the sheer number of colors ...

Inside the cool laser-cut box is an Arduino Uno and a 9V battery, plus a current-limiting resistor and the all-important buzzer. ... 4 thoughts on “ 1D LED PONG, Arduino-Style ” Joshua says: ...