Wet greasy looking cappings in the honey super are normal as are white cappings. One just has a bit of air under the cap and the other does not.
Wet greasy BROOD cappings are a sign of brood diseases or old brood comb that has been abondoned because it got chilled. Especially if they are pierced cappings, I'd do a matchstick/rope test for AFB. If I found ropey brood, I'd do a holst milk test for AFB. If that was positive I'd send some of it to Beltsville for a positive ID.