Segmenting areas of a lab by color of disposable glove can ensure lab workers don't cause cross-contamination by moving from one area to another. Working with one material then going to a different area is a potentially hazardous action that can cause cross-contamination in the lab. The supervisors/safety inspectors can do checks to see if anyone in the lab has caused cross-contamination. They use fluorescein (fluorescent powder) to dust the area in question, so you can see the contaminants under a blacklight. It's easy to find out where the person has been and if they've crossed into different areas where they weren't supposed to be. This will reinforce the idea that when someone leaves Zone A to go to Zone B, they take the old gloves off and put a different color of gloves on, so as not to take substances from one area and inadvertently put them into another area. In food production, it's also important to have a glove with enough color. If a shard from one of the gloves rips and gets into the food being prepared, it's ideal to have a fairly dark color glove so that the glove shard will be immediately visible. You want to have a darker color that stands out against whatever is being prepared.