This programs lights a row of RGB LEDs (WB2812B ICs, known as NeoPixels) in multi-colored patterns. It is a crosswalk pedestrian signaler for people who are walking across streets in the early evening when it is dark and there are a lot of cars still on the road. It is meant to fit in a clear or translucent plastic tube about 18-22mm inner diameter (the width of a 18650 lithium battery).
Pressing a button completes the path from the battery to the Tiny25, which lights 9 LEDs in a blinking pattern. With each blink the center color (#4 of 9 LEDs) is copied and shifted. If white is the center LED color on the first blink with the other colors of the sequence being= purple:red: green: blue: white :blue: green: red:purple, then at the second blink, the color sequence is= red, green, blue, white, pink, white, blue, green, red. The colors move from the center to the ends of the LED string. The RGB color values of the pseudo-random color selected for the middle LED comes from reading the flash values of the binary program code.