Our copper sinks have a living finish and will change with use. Acidic foods can cause it to lighten, however cleaning with soap and water and allowing to air dry after use will allow the patina to darken naturally. The front will maintain it's color more consistently as it should not come in contact with food etc like the inside does. I do have one myself and do know that they do darken back down naturally.

Please let me know if I can answer any other questions for your.

Thanks,

Cindy