So this is the weekend you’re finally going to tackle the cottage “to do” list. Job one: Wade through that giant coffee can full of screws to see if you have the fasteners you need for the tasks at hand. The simplest way to tell them apart is by color.
1. The black ones are drywall screws, cheap and useful for many odd jobs, but not very strong. The tint comes from a phosphate coating that prevents wet drywall compound from corroding the screw head.
2. Blue ones are masonry screws, used for fastening things to brick, mortar, block, or rock, though you have to drill a pilot hole first.