Switching backlight to RGB in the following monitor C24FG70
LED lighting is done inside the LCD panel (Example p.13 Fig.5), not in the monitor. So it's not possible (or easy) to directly access to the backlight module.

To enlighten the whole rectangle panel, high-current LED strips (e.g. 125mA) are positioned across the edges of the glass. Those LEDs are also very low-profile like this one.

So, RGB LEDs you've suggested don't have that high power to enlighten the whole glass (even if you use 50 of them).