How to change the highlight groups (colors) for hover box?

[Kevinizevbigie]

How do I change the highlight groups for popup box variables?

The highlight groups in the popup box (hover) do not match my codebase.

Code:

Popup:

I use a custom popup function for the above. But without it, it looks like this:

Popup function:

function! PreviewPopupOpts() abort
    return {
    \ 'col': -999,
    \ 'close': "click",
    \ 'wrap': 1,
    \ 'minheight': 5,
    \ 'minwidth': 50,
    \ 'maxwidth': 79,
    \ 'highlight': 'PopUpWin',
    \ 'moved': "word",
    \}
    endif
endfunction

let g:ale_floating_preview_popup_opts = 'PreviewPopupOpts'