You should have stopped. If you saw the yellow too late you may have been daydreaming or were too fast.

Standard is an anonymous fine (Ordnungsbusse) of 250.- according to Zürichs police, so no further consequences. But as you say it was icy and were unable to stop in time, it may well mean you were driving too fast; not above the speed limit but considering the circumstances. In such a case the sanctions may be quite a bit higher and will usually come with a temporary suspension of the license (I would expect one month if there was no danger of actually hitting something).