Answer: Alcohol-type neutral sealant may have this phenomenon, which is caused by the production of raw titanium chromium compounds. The titanium chromium compound itself is red, while the porcelain white color of the sealant is the titanium dioxide in the tinting effect. But the majority of chemical reactions in agricultural production system are reversible reactions, as well as the generation of side reactions. Temperature happens to be the key to these reactions, the temperature is high and a positive reaction causes the color to change, but the temperature drops and stabilizes and the reaction goes backwards, restoring the original appearance. Production technology and formulations are well mastered and should be avoided.