This doesn't appear to be something specific to YouCompleteMe but rather built in Vim syntax highlighting. So if you want to change the colors for ycm it looks like Pmenu is the highlight group you want. Put something like this in your .vimrc file. highlight Pmenu ctermfg=2 ctermbg=3 guifg=#ffffff guibg=#ff This sample creates a white foreground and blue background. If you would like to change it change guifg to the foreground color of your choice and guibg to the background color of your choice. The colors are hex codes so you will need to reference a color picker that understands hex codes if you are not already familiar with them Online Color Scheme Generator