The correct buttons depend on which rank bars you’re looking to portray. The OT used a consistent size, and the newer movies (Rogue One on) used mostly a slightly larger size. (some random scenes seem to have officers with OT-sized buttons for … reasons?)
OT sizes:
EAO:
01-901.2 = Red = Confirmed Good “Trslucent”
01-901.4 = Yellow = Confirmed BAD “Trslucent” [NOT WHAT YOU WANT]
01-901.6 = Blue = Confirmed Good “Trslucent”
01-982.4 = Amber = Confirmed Good
The above buttons are available from Newark and/or Mouser in the US (if I recall Newark does NOT carry the amber buttons). Non-US locations have some other options I can dig up if needed. Note that several listings on their site do NOT have the correct product image… but if the button model number is as listed above, you’ll get the right buttons.
I have the models for the more recent series saved elsewhere… if you still need them, ping me and I’ll look them up. I also found some slightly-less accurate (but 1/4 the price) options on AliExpress, for the post-OT larger sized buttons. Again, ping me.