1, the first-class rapeseed oil with different colors is light golden yellow, and the pure rapeseed oil is dark black. 2. After degumming, deacidification, decoloration, deodorization and other processes, the first-grade rapeseed oil with different refining degrees has the characteristics of tasteless, light color, high smoke point, less cooking oil fume and difficult solidification at low temperature. After refining, the content of harmful components in oil is low, such as glucosinolates in vegetable oil, but at the same time, many nutrients, such as carotene in soybean oil, are lost.