I also sort by color. I have a list I created and even put on my phone so I can check if I have a color or not.
I use storage boxes. I have cats and since we have forced hot air, dust bunnies galore. You would have to vacuum 5 times a day to keep up since a lot occur where only the cats can get to. I also have boxes stashed out of the light. Some thread does fade.
Most phone reader apps can handle a pdf.