Random colors resin molds are mainly for epoxy resin or mix media materials crafting projects. If use with UV resin, after un-mold, you may need to use UV lamp to cure the front as well. Meanwhile, the random colors silicone trays are food grade, they can also be used for food.
Clear color UV resin molds make UV light easily pass through the mold, and UV resin can cure easily. UV resin trays are also food grade.