Novation Launchpad used to be exactly that: you send MIDI CC messages with proper values and you can light up the grid (with different colors).

Did that a few years back, i guess this might still be possible

> used to be

Looks like they are still around? https://novationmusic.com/launchpad

Also seems to be in stock locally.

The device that I think popularized that design (citation needed) was the Monome (https://monome.org/) that looks like it is also still around and it has (always had?) some kind of open source license (https://github.com/monome).