Originally, we all had brown eyes until you get genetic inherited

blue eyes may contain brown spots

Blue eyes are considered as failure genetic but not negative mutation and nether positive mutation, it's variation of color which is rare like albino.

While some cats and dogs have blue eyes, this is usually due to another mutation that is associated with deafness.

Blue Eyed Parents Can Have Brown Eyed Children

Chris-chan have one blue eye and one green eye