LED is an industry acronym for Light Emitting Diode. These are usually small little “bulbs” that glow in different colors when they are “turned on”
(most common colors are red, green,yellow, blue or white)
RGB (Red Green Blue) or multicolor LEDs can be serial driven by a core32. Some tests have already been made with WS2812 ( APA106 ) LEDs and a core STM32 through J4B Pin.
Original Forum Thread here: RGB LEDs
It has been proven recently that the use of high brightness White and Blue LEDs are not good to human sight. The output light spectrum for these LEDs is some harsh for the eye. You should prefer using other colors LEDs or not using them too much.