color flop

Flop Index is the measurement on the change in reflectance of a metallic color as it is rotated through the range of viewing angles. A flop index of 0 indicates a solid color, while a very high flop metallic or pearlescent basecoat/clearcoat color may have a flop index of 15-17.

FI(Flop Index)最早由杜邦公司提出,可以翻译为动态指数,或转向指数,该指数越高,随角异色效果越明显,也被称为变色龙效果