It seems that some use of alpha channel with red background color are really not well managed, in youtube for example ( it happen only in some part of the youtube web page composed with red color).
the button of youtube or the red background in a bottom part of a video, i join the example :
does it related with Nvidia driver ?
i use a MSI laptop with Nvidia/Intel GPU and XFCE DE.
You are using a extension acc to the first picture. Does disabling it makes a difference?
nop, it change nothing !
I think to have seen this problem not only youtube web page, even in 3 differents browsers too.
And i do not remember well in few desktop apps also.
better example of the problem on red color !
problem solve, it was due to the setting of my external monitors asus VG27WQ, GamingVisual mode, set on sRGB, only this mode generate issue