Take a look at fillchars

http://vimdoc.sourceforge.net/htmldoc/options.html#'fillchars'

'fillchars' 'fcs' string (default "vert:YXXY,fold:-") global {not in Vi} {not available when compiled without the |+windows| and |+folding| features} Characters to fill the statuslines and vertical separators. It is a comma separated list of items:
item      default     Used for 
stl:c     '' '' or '^'    statusline of the current window
stlnc:c   '' '' or '-'    statusline of the non-current windows
vert:c    '|'     vertical separators |:vsplit|
fold:c    '-'     filling 'foldtext'
diff:c    '-'     deleted lines of the 'diff' option
Any one that is omitted will fall back to the default. For "stl" and "stlnc" the space will be used when there is highlighting, '^' or '-' otherwise.

Example: :set fillchars=stl:^,stlnc:-,vert:|,fold:-,diff:- This is similar to the default, except that these characters will also be used when there is highlighting.

for "stl" and "stlnc" only single-byte values are supported.

The highlighting used for these items: item highlight group stl:c StatusLine |hl-StatusLine| stlnc:c StatusLineNC |hl-StatusLineNC| vert:c VertSplit |hl-VertSplit| fold:c Folded |hl-Folded| diff:c DiffDelete |hl-DiffDelete|

Wouldn't mind finding some cool unicode characters to replace VertSplit and and Folds, but this is purely for looks.

HokieGeek / dotfiles

Take a look at fillchars #87