To use external css styles:
make here file or symlink 'default.css' to one of css-files, where css files may be
either
1) with 9 replaceable colors (%1, %2, ..., %9, see default_flat.cc)
or
2) with 14 replaceable colors (%1, %2, ..., %14, see default_nonflat.css)
or
3) without any such a colors at all, but with exactly predefined colors
