Portable infobox background

1. Id labels
* Infobox background is .portable-infobox
* Infobox header is .pi-title
* Infobox header is .pi-header
2. Add CSS to MediaWiki:Wikia.css 
In MediaWiki:Wikia.css the .pi-theme has to be added. I will name by its color so it would be 
.portable-infobox.pi-theme-red {
 background:lightsalmon;
}
.pi-theme-red .pi-title {
 background:red;
}
.pi-theme-red .pi-header {
 background:red;
}
.portable-infobox.pi-theme-blue {
 background:lightblue;
}
.pi-theme-blue .pi-title {
 background:blue;
}
.pi-theme-blue .pi-header {
 background:blue;
}
.portable-infobox.pi-theme-yellow {
 background:lightyellow;
}
.pi-theme-yellow .pi-title {
 background:yellow;
}
.pi-theme-yellow .pi-header {
 background:yellow;
}
3. Infobox theme-source name 
In the <infobox> row add theme-source which I will call "background"
 <infobox theme-source="background"> 
4. Infobox theme-source variable 
When using the infobox, include the theme-source variable 
{{Railway
 | background = red
 | title1 = Mid Sodor Railway
 | image1 = [[File:No_Image_Available.png]]
 | caption1 = The sheds at Arlesdale
 | locale = Sodor
 | terminus = Arlesburgh Bridge Street
 | stations = 9
 | name = Mid Sodor Railway
 | length = Example
 | gauge = 2ft3in
 | opened = October 1880
 | closed = January 1947
}}
{{Railway
 | background = blue
 | title1 = Mid Sodor Railway
 | image1 = [[File:No_Image_Available.png]]
 | caption1 = The sheds at Arlesdale
 | locale = Sodor
 | terminus = Arlesburgh Bridge Street
 | stations = 9
 | name = Mid Sodor Railway
 | length = Example
 | gauge = 2ft3in
 | opened = October 1880
 | closed = January 1947
}}
{{Railway
 | background = yellow
 | title1 = Mid Sodor Railway
 | image1 = [[File:No_Image_Available.png]]
 | caption1 = The sheds at Arlesdale
 | locale = Sodor
 | terminus = Arlesburgh Bridge Street
 | stations = 9
 | name = Mid Sodor Railway
 | length = Example
 | gauge = 2ft3in
 | opened = October 1880
 | closed = January 1947
}}
Category:Mobile-friendly