The white, blue and purple effects on Tik Tok's face are called "frozen face" or "cold face" effects. This special effect is achieved by using filters and special effects in the video editing process. White, blue and purple are chosen because these colors give people a cold and mysterious feeling and can create a unique atmosphere and visual effect.

This special effect is very popular on social media platforms such as Tik Tok for the following reasons:

1. Eye-catching: The unique color tone of the white, blue and purple special effects on the face can attract users' attention and make the video more attractive and unique.

2. Create mystery: The special effect of frozen face gives people a mysterious feeling, which makes people feel curious and surprised, and makes the audience more interested and interested.

3. Create an atmosphere: White, blue and purple tones can create a cold, dreamy or mysterious atmosphere, making the video more emotional and artistic.

It should be noted that filters and special effects are only a tool for video editing, and proper and reasonable special effects can enhance the texture and attractiveness of video. However, excessive use of special effects may make the video appear exaggerated or unreal, so when using special effects, we need to grasp and choose according to the specific situation and style.