Does anyone know where I can get some Yellow keycaps (doesnt matter if PBT or ABS) that let the LED shine through ie. like those keycaps in the Ducky Shine.
There are very few PBT double shots (to my knowledge), so you will get ABS.
Most backlit keycaps are terrible and the coating wears off, but more importantly, finding yellow caps with clear legends will proably be non-existent. Most companies use white, black or clear with white black or clear legends and use a colored LED behind it (Sharpies work on white ones to change color).
Yellow keys aren't common to begin with, neither are backlit keycaps, so finding one with clear legends is probably fruitless search.