RULER COLUMN

A Sublime Text plugin that shows ruler columns only on lines where the text overflows.

Menu > Preferences > Settings:

{
    "ruler_column": 120
}

You can also set the width (defaults to 0):

{
    "ruler_column_width": 0
}

Customising the color

In newer versions of Sublime Text (~= 3154) customising the color is straight forward enough.

Create a color scheme override in your Sublime Text User directory (find the User directory via Menu > Preferences > Browse Packages...). The override file must be the same name as the color scheme you want to override e.g. if you wanted to override the MonokaiFree color scheme then you would create a color scheme override file named MonokaiFree.sublime-color-scheme in your Sublime Text User directory. Here is an example:

{
    "rules":
    [
        {
            "scope": "ruler.column",
            "foreground": "#f92672",
            "background": "#f926729d"
        }
    ]
}