Given the fang and the uniform, I suggest one more tag.. Contact Lenses.

In the origianl tv anime, the photo of her father had inconsistent eyes with her memories or something from earlier.

At first I was like 'zomg alucard manipulating you'

Then the DVD came out and it turns out they just fucked up.

Yuri2Win said:
Given the fang and the uniform, I suggest one more tag.. Contact Lenses.

She has blue eyes in the manga and the OVA. They were only permanently red in the TV series. Considering the fact that her uniform is yellow here (manga, OVA) instead of blue (TV series), she IS supposed to have blue eyes.