How To Customize Colors, Fonts and more (CSS coding)

For more details, see first: Customize Piwigo


HTML (the Hypertext Markup Language) and CSS (Cascading Style Sheets) are two of the core technologies for building Web pages. HTML provides the structure of the page, CSS the (visual and aural) layout, for a variety of devices.

The CSS language (Cascading Style Sheets) is very useful to customize his gallery. Colors, fonts, positions of elements etc can be changed by using CSS.

Some useful tutorials and websites to learn How To use CSS

What you need

It depends on your browser :

  • Firefox : install the extension Firebug. Then press F12, or right-click to open the contextual menu and click on “Inspect this element”
  • Internet Explorer : press “F12”.
  • Opera : use Opera Dragonfly by pressing Ctrl + Maj + I on a Pc, or ⌘ + ⌥ + I for a Mac. You can also right-click to open the contextual menu and click on “Inspect the element”.
  • Chrome : press “F12”, and the icon magnifying glass to inspect an element.
  • Safari : go to Edition→Preferences→advanced et tick “Activate the dev menu…”. By doing that, you will have a new menu between Favorites et Windows. In there click on Display the web inspector”.

You might need to download several of these well-know browsers, because the render of a page may change according to the browser.

How To : search the selector

Each HTML element is accessible through CSS by selector. Read Syntax and Id and Class to understand.

Here is an example of how you can easily access to the html/css code of any web page, and change it. With Firebug, a new windows appears in Firefox (see Fig.01).

Fig.01 Firebug Menu
Fig.01 Firebug Menu

Fig.01 illustrates the HTML tab, where you can visualize the content of any web page -on-line or off-line-. You see what the browser receives and interprets. This windows is split in 2 zones.

  1. The first one (on your left) contains the HTML code.
    Info : You can see on the screen-shot a blue zone on the page : the mouse is over the <tr> which corresponds to that blue zone highlighted by Firebug
  2. The second zone (on the right) gives all the CSS properties applied to the HTML element selected. It shows also the selector used to apply the properties on that HTML element, and where the code is located -in a file and on what lines-. You can change on the fly the properties, by clicking on value and/or the property. The changes are applied immediately and can be seen on the web page without refreshing

How To : change the CSS properties

As we have seen, the value of any properties can be changed on-the-fly. The properties can be disabled, changed and created.

How To : save the changes in my Piwigo

In the forum someone gave you a piece of CSS code ?

You have played with one of the tools previously mentioned, and you want to save your changes ?

You might have noticed that Firebug doesn't change the files : if you refresh the page, you will lose all your changes
If you follow that tutorial, you will NOT lose your changes during updates.

Go to [ Administration » Plugins » LocalFiles Editor]]1) » Tab ”CSS” ]
There you can choose in the drop-down menu between local-rules.css and a all the themes enable on your gallery.

  • local-rules.css is a file loaded by Piwigo whatever the theme : if your CSS change need to be applied to all themes, select it.
  • If you select a theme, the CSS code written will be loaded only for that theme. In most of the case, it's recommend to apply the CSS code to one theme.\\Info :For a parent theme, his *-rules.css file will be loaded for him-self and his child themes! So a child theme can have several local-rules files loaded.

Now just copy/past your CSS code and save. The effects should be seen immediately : if not, try to refresh the cache of your browser and purge the Purge compiled templates, in [ Tools » Maintenance» ]

If you need to add comments to remember what a code do, just add two slashes before your text and the line will not be interpreted.

Illustration :

// It hides the menu of my gallery
#menubar {
  display: none;


Do I need to copy/paste all the content of a theme.css ?

Absolutely not!
The CSS in *-rules.css will overload the CSS contains in default CSS files like the theme.css of the theme you are changing.

Where are saved/stocked my changes ?

The CSS files generated by LocalFiles Editor are in the folder:


They are named *-rules.css with * is the name of a theme.

1) It needs to be activated!
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user_documentation/faq/css_code.txt · Last modified: 2015/06/02 12:55 by plg
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