I started trying to replicate your mod myself about a year ago but my studies have been getting in the way of finishing the project but now I've had some more time to try and get back to finishing it and had a few questions about the values for some of the components. Also, I don't have much experience in electronics so please excuse my ignorance

I decided to follow the design around the 4017 chip and 555 timer but couldn't figure out if I needed 1 resistor for
ALL the LEDs or 1 resistor for
EACH LED. The LEDs I'm planning on using is 1 Bright Red LED and 3 Bright White LEDs. I tried using the LEDCalc but I got confused as to which version I had to use; the Guru, Series, or Parallel model and ended up getting different values for the resistors.
The animation I want is similar to the fire breathing dragon except I wanted the red LED layer always on throughout and the 3 white LED layers to turn on and off, one after the other. How do I achieve this using the 4017?
Can I use just any NPN transistor and Trim POT for the circuit or is there a method I should follow to find a specific one?
I thank you in advance for any help I can get!
