Neat, I used such rgb leds to make a custom 200mm rgb pcfan (could only find green or red varieties on the market)
Something to look out for is that you’ve got two types, Common anode and common cathode. which need to be wired up slightly different. (though I lack the expertise to explain that further)\
edit. the reason the common anode and common cathode was relevant to my use case was that it needed to conform to the way the PC motherboard handles RGB, if you have more control over the power supply its likely just a matter of reversing the ground and live wires.
You should consider using the WS281x type addressable LEDs instead of those old 3-channel analog LEDs.
The WS281x Output Module is already part of Mycodo, and it only requires one hardware PWM line instead of three software PWM GPIO lines (one for each color).
Alternatively, Instead of having a bunch of wires coming from the Pi to your LED mushroom, you can use an ESP32 and install WLED on it to have some amazing control of the WS281x type LEDs (it can also control 3-channel analog LEDs) then you can automate commands from Mycodo using MQTT and remotely control your LED mushroom.
WLED is an amazing open source project you should check out, it also has some basic built-in automation functions as well, like timers and synchronization with multiple independent WLED instances, fully-custom-programmable infra-red-remote support, and a full HTTP and MQTT API for network-based remote control. https://kno.wled.ge/
I can control the brightness and color range of each LED on the strip using MQTT commands sent from custom Conditional Controllers I have setup in Mycodo…
Each LED is basically mimicking one of my dashboard gauges. It lets me see what is going on with my hydroponics system without having to open a browser and load a dashboard.