To choose a mask to fit properly you will first want to choose the proper mask style for your face size and special features, etc. Take a look at the “How do I choose the right dive or snorkel mask?” in our Gear Questions area.
Now you are ready to choose the skirt style and color. Most skirt “sealing surfaces” come in clear silicone. These are most popular because they allow ambient light in for the wearer and ease the “claustrophobic” feeling often times associated with the underwater experience.
Black skirts have all the functionality of the clear versions but they do not allow ambient light in. This may be an issue for some while many like it because the distractions of the ambient light are mitigated allow focused vision profile. Another benefit you cannot see the sinuses draining. Not cool if you are an Instructor or with someone you are trying to impress.
So, there you have it, choose your mask and when in doubt, ask and Instructor.