control an RGB LED (Kingbright LF-5WAEMBGMBW, 25 to 30 mA forward current per sub LED)
via a decade counter (M74HC4017B1).
Later I want to use these components in a more complex circuit. It is the first time that I use an Arduino, and I don't want to fry it or any of the other components. The Arduino is connected to USB at all times, i.e. there is no need for an additional power supply.