The sign help says:linehl={group}        Highlighting group used for the whole line the sign is placed        in.  Most useful is defining a background color.Is there a special group I can use (like SignRow)? Maybe there is a way to provide a specific colour instead of a highlight group? I tried sign define wholeline linehl=162 but it doesn't work. I'd like to use special colour for linehl so I want to avoid reusing any unrelated highlight group for this purpose.The only highlight group related to sign I was able to find is SignColumn which is not what I am looking for.
Which highlight-group should I use for :sign define x linehl?
highlight;signs
Highlight groups are an abstraction over the colors and styles that are available in the terminal or GUI. Vim has default groups built-in (and these are referenced by the syntax plugins), and a colorscheme provides corresponding color / style definitions.It is perfectly fine to define your own, custom highlight group, and then use that for commands like :sign and :match::highlight MySign ctermbg=162:sign define wholeline linehl=MySignIf you switch colorschemes often, or already have found a proper highlighting in your colorscheme, you can also just link your new group to it::highlight link MySign Identifier