Use skip_prefix() to get the part after "color:" (if present) and only
compare it with "reset" instead of comparing the whole string again.
This gets rid of the duplicate "color:" part of the string constant.
Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>