Plugin changes the appearance of KeePass, to make it look better at night.
You can enable it using hotkey
CTRL+T or using the menu
Tools -> DarkTheme.
The plugin allows you to create your own theme.
choco install keepass-plugin-keetheme
KeePass was created using standard Windows controls, which unfortunately were not designed for easy customization. They are extremely resistant to any attempts to change their appearance, especially from a plugin which has no control over their creation.
Therefore the plugin is not perfect and will never be, but is good enough to use it.