XF 1.3 userBanner

[iGloo']

Hi.
I, first, here is how my users banners looks like on my forum:
http://prntscr.com/3cju96

I would like to be able to change it by the image I made for my specific usergroups, like this one for example:
http://prntscr.com/3cjvfc

(Sorry, I tried uploading the image on noelshack to be able to put it directly here, wasn't working )

So, the question is, how to make this change.
I tried some change as:

.userBanner.banner-admin {
color: white;
background-image: url('pathToMyImage...');
}

I also tried

.userBanner.banner-admin {
color: white;
background:  #someColorCodeHere url('pathToMyImage...');
}

and I added as Brogan shared the optional CSS code in the usergroup banner:

userBanner banner-admin

Seems that it's not working.
That would be amazing if you can explain me. *__*

Brogan tutorial => http://xenforo.com/community/resources/creating-custom-user-group-banner-css.2000/

Thank you in advance.

 

[iGloo']

Up?