Short answer: The dye is permanent and it may fade over time.
We use the highest quality materials available to provide vibrant colors and normal wear and tear is expected to show if the disc is exposed to the elements. Different types of plastic will fade over time and discs may lose their crispness with prolonged exposure to direct sunshine. The first disc we ever dyed in 2011 is still crisp, yet the colors are a bit dull compared to when it was first dyed.