I finished the schematic and pcb 
:
Parts selection:
I pretty much selected the parts based on what was available and wouldnt take 5 years to deliver, along with costing an arm and a leg.
-The microcontroller im using is a xiao rp2040 cause it is cheap and easy to work with
-For the argb pins i just decided to use right angled 4 pin connectors and im gonna break the third pin manually
-Since the rp2040 uses 3.3v logic i need to convert it to 5v logic for the argb connectors and for that im using the SN74AHCT125N
-Then im using a 5.08 pitch 4 pin molex connector to connect to my 4 pin peripheral power connector which i can connect to my psu
-Then im using a polyfuse as a ressetable circuit breaker(holy larp) so that nothing shorts and protects my traces and psu from damage, and its a pollyfuse cuz it aint the 1900’s to keep replacing it.
-Bulk capacitor for the 5v line because LEDs draw current in spikes as they switch colours or brightness.
-Decoupling capacitor is for the IC noise
-Resistors is for protecting the LEDs and apparently it is standard practice for every WS2812 LED
Schematic and research took the most amount of time because i kept changing stuff because of availability then i kinda locked in and made the pcb in 30 min because everything else was done 
if anyone is wondering why im doing this ever since i switched to linux ONE singular LED in my fans is pink…AND it cant change colour properly so yeah
Now it is time for case, i dont need to worry about firmware because i have OpenRGB
