Created attachment 111087 [details] chrome window maximized see attachments I just applied the patch provided in https://phabricator.kde.org/D9773 and it seems it doesn't affect maximize button
Created attachment 111088 [details] chrome normal window (unmaximized) you see, it's the same
It seems we have no way to control this in the GTK theme. The proper solution would be for Chrome/ium to improve its mimicry of GTK 3.