Let’s suppose that we would like to customize a netscaler logon page by changing the “logo” and “background”.

Here are the steps you need to follow:
1. Backup your config by doing the following:
logon via SSH, and type:
cd /nsconfig
cp ns.conf ns.conf.save
or snapshot your appliance in vpx, or even better maybe both.

2. Customize your theme.
The easiest way of doing this is to use WinSCP or any other FTP client.
Navigate to following directories and replace the original files using your own ones:

/var/netscaler/gui/vpn/media/logo_notagline.png (Logo)
/var/netscaler/gui/vpn/media/bg_bubbles.jpg (Background)

Attention: While replacing the logo_notagline.png you may tweak the size of your own png-file defined on the ctxs.authentication.css file (Located here: /var/netscaler/gui/css)

border: 0 none;
float: right;
height: 44px;
position: absolute;
right: 71%;
top: 80px;
width: 221px;

3. Create the directory “ns_gui_custom” by typing this:
mkdir /var/ns_gui_custom

4. Now it’s time to create the “customtheme.tar.gz file”.
In order to get all the needed files into the theme and keep the stored path at the right level, you need to change to the “netscaler” directory by typing the following:
cd /netscaler

and then tar the contents of the /ns_gui symbolic link to the custom theme file by doing this:

tar -cvzf /var/ns_gui_custom/customtheme.tar.gz ns_gui/*

5. Head back into the Web Netscaler GUI,

expand the Netscaler Gateway node
select Global Settings
First column in the right pane is settings,
click on “Change Global Settings”
Switch to the ‘Client Experience’ tab
click the pull-down box to set the UI Theme to be ‘Custom’
then click ‘ok’

or from the CLI, Exit the Shell and type the following lines:
set vpn parameter -UITHEME Custom
save ns config

You should be good to go by now 🙂

In case something went wrong during the configuration, you can revert to default settings by:
Logon and type:
cp /nsconfig/ns.conf.save /nsconfig/ns.conf
save ns config

or if you took a snapshot, then just revert it.