(Vim) Wrong colors for ctermfg and guifg for highlight SpecialKey but not highlight LineNr

[0804d23d]

Here are my minimum .vimrc:

call plug#begin(has('nvim') ? stdpath('data') . '/plugged' : '~/.vim/plugged')

Plug 'sonph/onehalf', { 'rtp': 'vim' }    " https://www.dunebook.com/best-vim-themes/
    let g:airline_theme='onehalflight'

call plug#end()

set number
highlight LineNr ctermfg=Gray

set list
highlight SpecialKey ctermfg=Gray guifg=#bcbcbc
set listchars=multispace:•

let macvim_skip_colorscheme=1

colorscheme onehalflight

But why is the color of listchars=multispace:• not the gray color like highlight LIneNr (in both terminal and MacVim)?