I'm disappointed because of the vim behaviour under Ubuntu 13.04 and the issues I'm having the color reproduction.
I have problems when setting a colorscheme and I also tried to fix this issue with set t_Co=256
but I can do anything and nothing changes. I also tried different terminal emulators a and different settings but really nothing changes.
I tried Gvim and apparently it handles the colors correctly nd I have a much more consistent behaviour, now my question is: what am I missing when using gvim instead of vim?
I'm a new vim user so I don't know the potential of these two applications.
EDIT:
For example this is how the darkblue
theme looks like under vim
running in gnome-terminal
Assuming your Ubuntu environment is correctly set up (and judging from the screenshot, it is), you're probably just disappointed that most colorschemes don't come with high color support in the terminal.
You can use the CSApprox plugin (or one of its alternatives) to translate a GUI colorscheme to a high-color (i.e. 88-256 color) terminal. That will get you a closer approximation.