Phenomenon Resembling Play-of-Color In Sapphire

Nature has no rules. It is possible that the combination of fine milky particles and abundant transparent graining within the cloud in the sapphire were able to diffract light in a way that resembles play-of-color. Take a look.

Useful link:
https://www.gia.edu/gems-gemology/spring-2020-microworld-play-of-color-sapphire