According to the quoted standard (http://www.jedec.org/sites/default/files/docs/jstd033b01.pdf), those cards would indicated whenever your parts were exposed to humidity. If the indicator shows pink, you should dry the package before using the enclosed materials. Or at least that is what I understood from the brief skimming of the document I linked.
The pouch keeps the contents dry, while the card indicates when the humidity is within the recommended range for soldering. If outside that range, dont solder.
Some of these parts are also time sensitive, in that once exposed to free air (package is opened) they should be soldered within a given recommended time period (like 6 weeks) for optimum results.
The Moisture Sensitivity Level (MSL) procedures are generally for going through a reflow soldering process. For non-production hand-soldered items a person can normally ignore that precaution.