Due to the generic code name, the Numix team have decide not to use the code.desktop icon provided by the VS Code package.
So it's icon is configured as a common text editor by default.
How to fix it?
Looks like that the Numix team has provided an alternative icon with the name of vscode.desktop, in order to fix it we need to:
code.desktop to the local user directory:cp /usr/share/applications/code.desktop ~/.local/share/applications/vscode.desktop
vscode.desktop and rename all Icon properties from Icon=code to Icon=vscode.The result should be something like this:
[Desktop Entry]
Name=Visual Studio Code
Comment=Code Editing. Redefined.
GenericName=Text Editor
Exec=/usr/share/code/code --unity-launch %U
Icon=vscode
Type=Application
StartupNotify=true
StartupWMClass=Code
Categories=Utility;TextEditor;Development;IDE;
MimeType=text/plain;inode/directory;
Actions=new-window;
Keywords=vscode;
X-Desktop-File-Install-Version=0.22
[Desktop Action new-window]
Name=New Window
Name[de]=Neues Fenster
Name[es]=Nueva ventana
Name[fr]=Nouvelle fenêtre
Name[it]=Nuova finestra
Name[ja]=新規ウインドウ
Name[ko]=새 창
Name[ru]=Новое окно
Name[zh_CN]=新建窗口
Name[zh_TW]=開新視窗
Exec=/usr/share/code/code --new-window %U
Icon=vscode
