The standardization of colors or more commonly known as “color management” is an important aspect of digital photography. Because a picture that looks really good in a one device doesn’t mean it’ll look the same in others due to various reasons such as the technological differences of the output device (whether it’s a LCD or CRT, etc) & other similar hardware differences.
So to test how a picture would look in a different device then some sort of a color manager can come in real handy for adjusting color levels etc to minimize “incompatibilities”. Although almost all the major operating systems with a color manager of their own (plus the GPU driver too has a utility of their own, most of the time as well) but those utilities aren’t useful for the above mentioned task as they’re not designed for digital photographers.
In that case, if you use Ubuntu as your primary operating system (or GNU/Linux in general) then Gnome Color Manager is a simple yet a powerful color management utility that can be used to expand the default color management feature that’s built into the OS with ease.

Main features…
*. Being a Gnome application, it comes with a highly simplified UI which is user friendly.
*. Comes with few different color profiles of some popular devices too.
*. Easily add/remove devices (if your device is supported it’ll detect it automatically).
*. Has three inbuilt pictures for testing the output (you can use your own images of course).
*. Creates TRC graphs.
*. Shows a gamut of sRGB color space.
*. Change color profiling modes.
*. Color calibration… and a lot of other details will be available depending on your hardware.
You can install Gnome Color Manager in Ubuntu 12.04 Precise Pangolin, 11.10 Oneiric Ocelot, 11.04 Natty Narwhal, 10.10 and 10.04 by using the below command.
sudo apt-get install gnome-color-manager
Yep that should do it.