How do I change the width of scrollbars in Gnome?

The option to configure this is not in the "Appearance" application in the Preferences menu.

Solution 1:

In the file ~/.gtkrc-2.0, add the following lines:

style "wide-scrollbar-style"
{
  GtkScrollbar::slider_width = 24
}
widget_class "*Scrollbar" style "wide-scrollbar-style"

sudo apt-get install gnome-color-chooser

Then launch: System → Preferences → GNOME Color Chooser. Under the "Specific" tab, you can change the scroll bar width. Then Click Apply.

Screenshot of GNOME Color Chooser