Splash of Colour through Binary Segmentation

In Korean, it's 컬러추출필터 and in Chinese 局部彩色.

This is a technique that remains specific colour tone while making every others monochrome.
Main theme of my implementation is use of Bilateral K-means clustering (which simply means k = 2) after RGB -> YCbCr Conversion. For K-means clustering, I didn't consider Y (luminence value).

Demo Result