Quantity   Component name
1 × Atmel ATtiny13A The smallest commonly available member of the Atmel AVR processor family, with just 1K of flash, 64 bytes of memory, and available for a little more than a buck. http://www.taydaelectronics.com/attiny13v-attiny13v-10pu-microcontroller-ic.html
1 × A strand of WS2812 RGB LEDs These are increasingly common and inexpensive. You could use any of the NeoPixel lights offered by Adafruit, but I ordered a 4 meter long strip of LEDS using Amazon Prime. https://www.amazon.com/gp/product/B01B1D4T74/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
1 × A 5v power source Long strings of LEDs can draw lots of power. For experimenting, I ordered this 5v power supply, again, through the miracle of Amazon Prime. https://www.amazon.com/gp/product/B01JI373AY/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1