Why does her eye colour keeps changing? In some panels it's blue and in some it's red

I think the red eye one is to hide here blue cross eyes....i think

Her actual eye color is blue with a cross pupil, and it’s a sign of her ‘tribe’. Serena is also a part of said clan and has then same eyes and hides them as well. The red eyes are contacts so people don’t notice her heritage since that’s what caused her to be sold as a slave in the first place.