Color scheme options added to FZF_DEFAULT_OPTS. See https://github.com/junegunn/fzf/wiki/Color-schemes for documentation.
FZF_DEFAULT_OPTS
attribute set of string
{ }
{ bg = "#1e1e1e"; "bg+" = "#1e1e1e"; fg = "#d4d4d4"; "fg+" = "#d4d4d4"; }