Color TimeSeries thresholds?

Hi guys-

I have been plotting some signals in a timeseries, and I'm wondering if there's any way to do the following: In many cases, there are discrete thresholds associated with a signal that correspond to qualities. For example, if the value rises beyond 100 degrees, it is considered "high" quality as opposed to "good". I would love to display this on my timeseries as green for good, yellow for high, etc. and thus have a continuous signal with multiple colors.

I have done this in the past with a 3d patch, with the third dimension being a numeric quality code. Applying a colormap to this 3rd dimension and then presenting it with the color dimension flat works, but I can't use all the nice features a timeseries provides. Does anyone have any ideas?

Thanks!

Colin