I want to change autocomplete menu background color of neovim.please find my attachment.
You can use the
highlight command with the highlight groups
PmenuSel. Specifically, the background can be changed with the
Pmenu group like this:
hi Pmenu ctermbg=10 ctermfg=15 guibg=#ffffff guifg=#000000
Above I put both cterm and gui settings, but the gui part can only be used by setting termguicolors
set termguicolors, somewhere in your init.vim.
You can read more on highlighting on