Pulled deli ham from the fridge and noticed a rainbow-like shine on the slices. Is that normal?

surface of the ham appears excessively shiny or slimy, it may be a sign of bacterial growth. In such cases, it is best to err on the side of caution and discard the meat.

In addition to visual cues, your senses of smell and touch are valuable tools in determining the freshness of deli ham. Fresh ham should have a mild, slightly sweet aroma. If the ham emits a sour, ammonia-like, or otherwise unpleasant odor, it is likely spoiled.
Touch