In the one used in Ubuntu The Yaru design theme has been updated to use orange instead of eggplant for all button, slider, widget, and switch elements. A similar change has been made to the icon set. The color of the active window close button has been changed from orange to gray, and the color of the slider handles from light gray to white. Unless the change is reverted, the updated color scheme will be offered in the release. Ubuntu 22.04.
As a motive for changing colors, the limitations of the libadwaita library are noted, which, starting with GTK 4.4, includes components of the Adwaita theme used in GNOME. This library does not allow more than one accent color and applies a gray color to the window close button in order to achieve uniform title elements.
Source: opennet.ru
