When hovering over the Atom window it is
visible that the mouse cursor doesn’t match the default GNOME desktop
environment mouse cursor theme, Adwaita.
X11 default mouse cursor is defined in /usr/share/icons/default/index.theme
and by a regular CentOS install is left to dmz-aa.
To have a coherent theme across GNOME GTK3 windows and Atom, change it the X11 theme to that of GNOME:
# sed -i 's/dmz-aa/Adwaita/g' /usr/share/icons/default/index.theme
