Using crystal violet lactone (CVL) as chromogenic reagent, cetyl alcohol (CA) as solvent, pyrogallic acid (PA) and 4-methoxyphenol (MP) as color developer, the obtained mixtures exhibit reversible thermochromic properties. The maximum absorption wavelength of the reversible thermochromism compound is 610 nm. The blue intensity of the compound can be characterized quantitatively by absorbance. When the amount of CVL is determined, and the quantity variation of the developer and CA are in proportion, the composition of the mixture has little infl...