Hi!
Since last two Firefox Developer Edition updates or so, eyedropper shows different color from the real one.
As an example, color #1a4270 becomes #263871. When tried Firefox 76.01, it shows the right colour.
Installation info:
Name Firefox
Version 77.0b6
Build ID 20200514211331
Update Channel aurora
User Agent Mozilla/5.0 (X11; Linux x86_64; rv:77.0) Gecko/20100101 Firefox/77.0
OS Linux 5.4.0-29-generic