DenbroughtYes, it supports switch LEDs. Any of your standard LEDs will work, but most people recommend 2x3x4mm or 1.8mm due to some thick keycap sets having clearance issues with 3mm LEDs.
1.8mm only come in pretty standard colors, whereas you can get some more interesting colors of 2x3x4. AliExpress seems to be the best place to buy them from what I've found, but someone feel free to mention other options if you know of any.