Switching and opening windows in Firefox

[Ludovit]

When opening or switching between windows in Firefox, a bright white flash appears. Even though it only lasts a fraction of a second, it causes significant eye strain during extended browsing sessions. When my eyes get tired, I deal with this by closing my eyes whenever I switch between windows. Would it be difficult to modify the switching process so that a dark background appears instead of the bright white flash? It would be much easier on the eyes. Thank you.