Since you say you're just making a starter it's a part of the process (usually starts sometime around 48 hrs or so, so your weather may have slowed it a little, ideally it'd be 65-75F room temp-- I don't know about you but we certainly are keeping the house that warm this winter) and it will pass as it continues to ferment. Or as my bread book puts it: "...will eventually brighten as it nears the finish line."
If however if you're feeding your already established starter and gets musty or cheesy smelling--or, if you are particularly brave, tasting--it has overfermented (too long or too warm) and has become an rather inviting potential host to undesirable 'bad' bacteria--at which point I personally would probably just start over (because I don't know how I'm to tell if it's already throwing the kegger or just stocked and tricked out the frat house in preparation) but I dunno maybe someone else would have tip on how to salvage it...Doesn't sound like this is your situation though (at least right now).
Basically, it sounds to me like the normal run of things in which case ride it out for another day or two (like a brief bout of morning sickness) and see if it gets better.
Maybe this helps than again maybe it's just confusing, CJ