Vim FoldColumn color different on Debian / Ubuntu

I sync my [.vimrc file](https://raw.githubusercontent.com/denten/.dotfiles/master/.vimrc) between two machines, one running Debian testing and the other Ubuntu. On Debian everything works fine. On Ubuntu, the fold column is gray instead of black, even though black is specified:

: hi FoldColumn ctermbg=Black ctermfg=Black

If I comment out line 213, the fold column turns black, but then foldmarkers default to white (the whole point is to hide them black on black). If i just do:

: hi FoldColumn ctermfg=Black

The FoldColumn is gray again. I do not find plugin conflicts with

-r "FoldColumn" .vim/

. Any ideas?