Not really. Darker lens can decrease the amount of visible light that passes through the lenses compared with lighter lens tints, but they don't necessarily provide greater protection from UV rays .
The amount of UV protection that sunglasses provide cannot be determined by the color of the lenses. It should depend on the lens material and any additional UV-blocking coatings that may be applied.
I don’t believe that. If you pursue for more UV protection, you should have your optician make sure your sunglasses block 100 percent UV, regardless of the color of the lenses.