[HELP] How can I change style the signature help / argument hints?

[Wallace Rutherford]

Hi everyone.

As this is my first message I would just like to say, you people are doing an incredible job, what this project has achieved is simply amazing!

After many years of developing Go in Vim with vim-go, UltiSnips and SuperTab, I have recently started using YouCompleteMe instead of the autocompletion provided by vim-go. After some basic configuring, everything works great, not a single glitch.

For me the "signature help" is YouCompleteMe's killer feature and the golden standard, because it allows people coming from VS Code to feel right at home when we pair-program, we all know how hard it is to use an unfamiliar editor.

I am working on my colorscheme, and I would like to customise the style of the signature help. 

Here's a summary of my setup:

• I only use terminal Vim
• my Vim colorscheme uses exclusively the ANSI terminal palette (16 colours, plus FG and BG, with and without "reverse")
• my Vim is set to use strictly only 16 colours anyway (t_Co=16)

And here's what I've learned so far about the highlighting of the signature help:

• it uses some form of syntax highlighting, but it is not the same as the rest of the buffer
• some parts of its background seem to be linked to the Pmenu style
• ...and some other parts instead seem to be affected by the definition of CursorLine group
• the current parameter is simply the inverse (using the YcmInverse group)

I managed to have a usable highlighting of the signature popup by removing any highlighting from the CursorLine, and choosing a sensible—for me—Pmenu style.

I looked in the source, but I couldn't find any better way. 

Is there a way to style the signature help independently from everything else? For example, I would like to

• not use any syntax highlighting
• set the background myself, so that I can have more freedom with Pmenu and CursorLine
• style the current parameter more subtly, without using "reverse", so that both argument name and the argument type have the same style, this way it would be clearer what is the current one

Thank you again to anyone who can provide any additional insight! 🙂

Wallace