Cut 'em open and pour them in a jar with a tight seal. When you need a pack, microwave hell out of some and rubber band them into a piece of coffee filter.
The colored beads indicate how water saturated they are. When they’re nuked and dried out, they change color. YMMV as some manufacturers use different colors or none at all. Whatever. Nuke 'em and reuse.
It’s an exciting hobby.
Op says s/he heats them when they need them. These are standard silica gel beads, dehydrating them makes them usable again. They are not the iron oxygen absorbers.