If they have their own method that means that they use some interface for that. I just want to know how can i use this interface. It should be some static method or class because I don't see any reason to do a method like this not static. I would create my own function but I can understand the algorithm, and how it is working at all, it is not RGB and it is not hex, what is the color scale they are using for color? Also in the input field we can clearly see that this is the function that they save as a string, then this string they parse somewhere and call. Interesting how it is working and how developers can use it.