Homemade PCB with 120 RGB leds - help

[Ōkami]

Good Morning / Good Afternoon, I would like to know how we can control 120 RGB Leds for a max consumption of 500mA not to fry the USB port of the computer. I inquired about lots of sites, saw lots of videos and asked for help though I’m a little lost. Hence my question, what are the possible solutions to control 120 RGB Leds for a maximum consumption of 500mA  (I will use later the QMK software for the keyboard).

[4sStylZ]

Answering by another question : did you have studied How factory keyboard like logitech or corsair rgb work with full 1/key rgb led ?
My gf have one and this don't fry the usb… 

[Findecanor]

LEDs are put in a matrix, similar to a keyboard matrix, with only one portion of the matrix activated at once. That takes care of the power consumption. By flickering faster than the eye can notice, it looks steady. The brightness of a LED is controlled by how much relative time it is lit vs. dark.

Dedicated RGB LED controller chips are usually used to get fine-grained control of colour of each RGB LED, and so that the main microcontroller can do other things.
I would looking at the ISSI IS31FL3733 chip. You'd need two of them for 120 keys though, but that should work (Input Club K-Type/Massdrop Ctrl uses two for both backlight and sideglow). There is support for it (and others) in QMK.