给定一个RGB值，找到数据库中最接近的匹配的最佳方法是什么?

I have a rgb value and if it doesn't exist in the color table in my database I need to find the closest color. I was thinking of comparing all values and finding the difference(in red,green,and blue) then take the average. The lowest average deviation should be the closest color. There seems to me like there should be a better way. Any ideas?I have a rgb value and if it doesn't exist in t