Last moment's image of my eye's pupil causes it to look like drops of ink.
That is, along with the muscles of the eye and face.
The blood rush from the back of the eye changes the color of the pupil.
The blue of my iris gets mistaken for my pupil.
Blue dispersing back from the eye changes it too.
Green is simply the 'filling-in' phenomenon.
Same with yellow.

Are dreams merely a filling-in between life lived from one day to the next?
Is spiritual vision merely a filling-in of beliefs with physical sight?