The leaves of a plant change color due to environmental stress. If your Aloe leaves are turning brown a few reasons could be the soil is too dry or too wet, the temperatures are too hot or too cold, or too much hot sun. My large Aloe Vera growing outdoors has brown tips because of the dry air here in the desert. I don't cut them off because I don't like the look of blunt-cut leaves. If they're really bothering you, you can take them off.