Ok I’m not sure if this has been brought up yet by any body else, but I’m going to talk about it.
So it’s pretty obvious that the main colors for Maggie (green) and Gil (blue) are the colors that represent their sins, although swapped between them.
But they are still associated with the color that is suppose to represent their sin, as it is their favorite color. Maggie wears unmistakable blue clothes and Gil wears a green shirt, but his green is a little harder to tell in comparison.
But there is one thing that they don’t have control of that still has the color of their main sin. Their eyes.
I know, Maggie’s eyes look green overall, but the pact changed her eye color including pupils right? I used the eyedropper tool in photoshop and took a look at her pupils’ color.
So they’re a hue right between green and blue. Not blue enough to be that much different from the main color green though.
Now let’s look at Tuls and his eyes.
Ok so his eyes are almost the same exact color, falling in the same section between blue and green. They both have a color with their eyes that represents the sin of lust.
And now back at Gil.
He still hasn’t made his pact yet, and seems blue through and through with appearances he cannot control.
But look at his demon, Nevy.
She has green eyes. Unmistakably green eyes when compared to blue.
Whenever Gil will make that pact of his, his eyes will literally be “green with envy”.