Tools > Preferences > Code Editor > PL/SQL Syntax Colors. Here you can choose Twilight scheme.

No, there is no official method. There is a way to change it manually through, through editing a jar file. Here is the full video if it helps you out. By default you can only change the Syntax colors + background of the editor.

Try to do this

OS: Debian Linux

Desktop: Gnome 40 JDK: Open JDK 11

edit ~/.sqldeveloper/{version}/product.conf

add (the system theme will be used):

SetJavaHome /{path to open11jdk} AddVMOption -Dswing.defaultlaf=com.sun.java.swing.plaf.gtk.GTKLookAndFeel

If you would like to use a different theme that is not set for the system: edit ~/.sqldeveloper/{version}/product.conf add (after the above changes): GTK_THEME={theme name}

export GTK_THEME

Windows 10:

edit: {user}/AppData/Roaming/sqldeveloper/{version}/product.conf

add:

AddVMOption -Dswing.defaultlaf=com.sun.java.swing.plaf.windows.WindowsLookAndFeel

Sqldeveloper will use the current default Windows 10 theme