I don't see what you look at, when you say there is a difference I miss the point
Also, I see still no difference in the mentions. Here in ProSilver 4 screenshots of a mention. w/wo "friend", dark and light mode
Always with F5 and CTRL-F5 also after every change, just to be sure.
Same for ProLight - no difference.
What you have in ProSilver is that there is alteration of the background, for the post list and for quote parts.
But again other than that I don't see a relation with my friends.
And as for foes, the posts are collapsed initially, but can still be seen when needed.
(don't worry "weerwater" it's just for a technical est...we're all friends ! )