problem with background and mix-blend-mode: difference for menu

[Dawid]

www.argoth.pl
Safari / iMac

I'm having a problem with the background and the "Make Texts mix-blend-mode: difference" feature for the menu. If I set the background globally (in "Apperance/Customize")—in my case, a large centered logo—and add a white background color, the "mix-blend-mode: difference" feature doesn't work, and the menu becomes invisible. However, if I add a background color directly on a specific page, the feature works, but it covers up the background I set globally (in "Apperance/Customize"). Unfortunately, when I set the background on a specific subpage, I can’t adjust its settings (stretched, centered, etc.)

Is this a bug in LayTheme or am I doing something wrong? :)