How can I change the text colour in a Plasma-desktop notification?

I am using Plasma-desktop notifications for all kinds of things, often from scripts using kdialog or notify-send. My Plasma desktop uses a dark background with a light foreground (text). Until a few months ago, all was well, but after a system update (in May?) my notifications kept their dark background but started using dark text as well for the notification body. Hence, all I can read is the title. I looked at my current colour scheme in ~/.local/share/color-schemes/*.colors, setting all text (Foreground*=255,0,0) to red, but the notification fonts did not change. This document provides some specifications and mentions that ForegroundInactive should be used for the body text. However, this may be in a section of the colour scheme that is currently lacking. Also, the document is about three years old. I'm using KDE Plasma v.5.25.5 on Gentoo Linux. How can I change the colour of the (body) text in my notifications?