Customisation to sonokai to make greys a bit darker for better contrast

sonoakai_atlantis_custom.vim

let palette = {
  \ 'black':      ['#1c1e1f',   '237'],
  \ 'bg0':        ['#273136',   '235'],
  \ 'bg1':        ['#313b42',   '236'],
  \ 'bg2':        ['#353f46',   '236'],
  \ 'bg3':        ['#3a444b',   '237'],
  \ 'bg4':        ['#414b53',   '237'],
  \ 'bg_red':     ['#ff6d7e',   '203'],
  \ 'diff_red':   ['#55393d',   '52'],
  \ 'bg_green':   ['#a2e57b',   '107'],
  \ 'diff_green': ['#394634',   '22'],
  \ 'bg_blue':    ['#7cd5f1',   '110'],
  \ 'diff_blue':  ['#354157',   '17'],
  \ 'diff_yellow':['#4e432f',   '54'],
  \ 'fg':         ['#e1e2e3',   '250'],
  \ 'red':        ['#f76c7c',   '203'],
  \ 'orange':     ['#f3a96a',   '215'],
  \ 'yellow':     ['#e3d367',   '179'],
  \ 'green':      ['#9cd57b',   '107'],
  \ 'blue':       ['#78cee9',   '110'],
  \ 'purple':     ['#baa0f8',   '176'],
  \ 'grey':       ['#82878b',   '246'],
  \ 'grey_dim':   ['#55626d',   '240'],
  \ 'none':       ['NONE',      'NONE']
}