Theme

By default vim-clap would use the colors extracted from your current colorscheme, which is not guaranteed to suitable for all the colorschemes. You can try the built-in material_design_dark theme if the default theme does not work well:

let g:clap_theme = 'material_design_dark'

material_design_dark-theme

You could also set g:clap_theme to be a Dict to specify the palette:

" Change the CamelCase of related highlight group name to under_score_case.
let g:clap_theme = { 'search_text': {'guifg': 'red', 'ctermfg': 'red'} }

ClapDisplay and ClapPreview are the most basic highlight groups for the display and preview window, which can be overridden if the provider has its own syntax highlight, then checkout the related syntax file for more granular highlights directly.

If you are keen to explore and even want to write your own clap theme, take autoload/clap/themes/material_design_dark.vim as a reference.

See :help clap-highlights for more information.