How to customize on-screen notifications?

There is no official way of modifying the notifications, but many changes can be made to the notifications bubbles by installing a 3rd party patch which allows various changes to be made. More details are available here: http://www.webupd8.org/2012/06/closable-movable-notifyosd.html

To install:

Open a terminal window and enter these commands one by one:

sudo add-apt-repository ppa:leolik/leolik 
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install libnotify-bin
pkill notify-osd

This installs a patched version of the notify-osd package. Then you will need to install the GUI configuration tool, to do this enter these commands one by one into a terminal window:

sudo add-apt-repository ppa:nilarimogard/webupd8
sudo apt-get update
sudo apt-get install notifyosdconfig

To use the congfiguration tool type "notify" into the dash and launch the NotifyOSD Configuration application.

Modifying the Notifications

• From this application you can change the colour of the notifications by clicking on the Background Colour box (in the picture below I've turned it a horrible green!).
• To change the length of time the notifications appear on screen adjust the value in the Timeout box

The tool also includes other customisations including:

• Change font, opacity, size, corner radius
• Disable fade out
• Close the notifications on click
• Enable/disable "use Dash background colour for the notification bubbles"

Changing the position

To change the location that the notification appears you need to open a terminal and enter the following:

gsettings set com.canonical.notify-osd gravity #

the # in the above code should be replaced by a number between 1-6 depending on where you want the notification to appear (3 doesn't seem to work for me though):

1 - top-right corner
2 - middle-right
3 - bottom-right corner
4 - bottom-left corner
5 - middle-left
6 - top-left corner

• In the Position drop down box you can choose from Fixed and Dynamic, dynamic gets rid of the gap between the notification bubble and the top dash

I could not install notifyosdconfig using the PPA on my Ubuntu 15.04, but i got it working by doing the following:

sudo apt-get install bzr libqt4-dev
bzr branch lp:notifyconf
cd notifyconf
make
./notifyosdconf

Which does not fully install it (you won't be able to find it in the dash) but it does work.

In case anyone might come to this question sometime with a Lubuntu distro (or any other of the 'Buntu flavors), please note that things might be quite different there. On Lubuntu, the best and quickest way is to use xfce4-notifyd-config; however, there is no way to have the notification dialog appear anywhere in the top center; merely the four corners are supported. But for those that don't need more, this will be sufficient by far to get the notification dialog out of the way when something else has been placed there and would constantly interfere resp. overlap.