See the screenshot. The arrow for the panel is drawn in the colour corresponding to the area to the left of the panel, whereas the arrow appears on the top-right of the panel.
There are two solutions here: either we reverse the gradient or colour the arrow based on the right hand side. :epang said we should do the latter.
Pushed by firstname.lastname@example.org:
Apply different color to protections panel arrow in RTL to match gradient. r=johannh
Can confirm with the current Nightly build 70.0a1 (2019-07-28) that the panel colors are in order.
Clearing the QE+ flag since this shouldn't be enabled(by default) on the current beta builds.