Since the seven groups of gods created the species, and each group is associated with a color, their species often has a specific eye color. Humans are created by all of the gods and therefore tend toward brown eyes. Some humans have other colors, like blue, and this has given rise to the myth that this means they must have some of the corresponding species as an ancestor, like jhaikan in this case. Since jhaikan are nefarious, the idea is that this person must be, too. This results from humans trying superficial means of understanding others, but it generally leads to misunderstanding instead. This is known as the Iris Myth.
There are eye colors that are a mixture and suggest mixed ancestry. Gray human eyes suggests karelian because these eyes sometimes appear green. They can also suggest jhaikan by appearing blue. Races often have different eye colors than their species. Niquerra have orange like the gods of the orange sphere whose influence they resemble. Sorelia have random colors and sometimes two different ones, per eye.