On the assumption that this aspect of Mandriva works like my Slackware system, try locating a file in /etc called 'DIR_COLORS' or a similar filename. This is where the colors of various things in the console are determined.
As for when a thread is resolved or closed, it isn't really indicated other than if you end it with a post saying that your issue is resolved. Otherwise, threads basically stay open forever, and will gradually move into the distant archived threads eventually and be forgotten about