Why are some stretch films light yellow in color

Why are some stretch wrap films light yellow in color? Normally, the wrapping films we see are mostly transparent or solid colors, such as black, blue, yellow, and other colors, with very few other colors. So why do light yellow wrapping films appear?
The light yellow color of the stretch film is mainly caused by temperature control during production. The production process of stretch film has become very mature today. Some manufacturers try to change the formula to produce stretch films with different properties, mainly reflected in three aspects: color, stretch rate, and self adhesiveness. A single color change may not necessarily affect the use of stretch film. It should be noted that many times, due to different melting temperatures set during processing, the color of stretch film may change, but it will not affect transparency. This is a good stretch film. If the stretch rate and self adhesiveness can decrease, it is a poor stretch film, which may contain impurities.
Strictly speaking, stretch film is only available in two types: colorless and colored. The appearance of pale yellow is mainly caused by additives such as Dov and colorants, or changes in processing technology. If the color is light and the stretch rate and self adhesiveness are not affected, it can be used. If the color is unnatural, the quality will generally be poor.
If the color of the wrapping film is light yellow, but there is no change in transparency, stretch rate, and self adhesiveness, and there is no odor, it can be used. If the four indicators change, do not use it anymore.