Very simple but smart doorbell

Description: This smart doorbell will feature a simple button, a proximity sensor and prominent rgb led indicator that changes color as a visitor approaches. It is supposed to have at least 3 parts, the fixed wall mount, removable rechargable battery and the actual doorbell. The three components will be held together magnetically. The goal is to have a simple, elegant and functional design that will have minimal manufacturing cost. It should focus on simplicity and affordability. Please see attached image for more info. Wants: Evaluation will be based on it's simplicity, originality and overall look and feel. Project Link: https://www.cadcrowd.com/contest/1958-very-simple-but-smart-doorbell