EDIT: A number of users suggested that this effect rises from the colour banding present within Apple's wallpaper that comes prepackaged with MacOS Sonoma.
After capturing a screensnip, I can confirm that this effect is generated by the launchpad screen overlaying the colour banding in the wallpaper.
EDIT: A number of users suggested that this effect rises from the colour banding present within Apple's wallpaper that comes prepackaged with MacOS Sonoma.
After capturing a screensnip, I can confirm that this effect is generated by the launchpad screen overlaying the colour banding in the wallpaper.