Hetian jade safety buckle usually looks very white, why is it blue when taking pictures?

The colors are white and blue, which are typical characteristics of Korean materials. In my opinion, this is not authentic Hetian jade, but Korean material. I suggest you send it as a photo, or go to Zhuo Yixuan for online identification and ask the experts there. They have been immersed in jade for many years and are very knowledgeable in this respect. They are also very authoritative in the circle of jade friends, and the appraisal results have certain credibility.