> I purchased these lids for 1 cup, 2 cup, and 4 cup Anchor Hocking glass storage bowls.> All three sizes fit perfectly and seal tightly on my Anchor Hocking glass storage bowls.> The lids may be a little thicker than the original Anchor Hocking, and so may last longer.> Of course, these also fit the corresponding Pyrex storage bowls> As far as I can tell (and I've looked into this), the different colors don't mean anything. I don't know if some colors are more durable than others. But, the colors are useful for color coding, e.g., red for beef, orange for pork, yellow for chicken, green for fish, etc.RECOMMENDATIONS> The lids should NOT be used in the microwave. However, if a lid (and the contents of the container) is frozen, it is likely to crack if you try to pull it off. It is best to microwave frozen storage containers for 1--2 minutes before removing the lid.> I've found that flat round silicon lids (sold separately) work great in the microwave for heating food in the glass storage containers. Not for storage. Only warming in a microwave.> You may be able to get longer life out of all of your plastic food containers by NOT using a forced dry cycle in your dishwasher. When I switched between my old Frigidaire dishwasher (which had forced drying), to my new Bosch dishwasher (which does not have forced drying), I noticed that my plastic ware lasted much longer. Even if your dishwasher has forced drying by default, you can usually choice a cycle which does not used forced drying. Turning off forced drying saves a lot of $ in electricity, and your plastics will last longer. Without forced drying, ceramics and metals will usually dry fine with just the heat of the wash. Plastics will be wet, but can easily air dry if the dishwasher drawer is left open for a while, or can dry on your countertop.> Having several sets of lids in different colors is convenient for color coding.> Click on “Stoney” just below the product title to see my other reviews