Mehhh Brain gives prompts 2

Your purple eyes (Ft. Dreamtale Twins)

Nightmare never had green eyes.

Not even after his corruption.

..Sure, it glows a bit green, but that was it.

"Brother- your eyes- they're purple-"

"...What do you mean? They were always purple."

(Basically, Dream was too focused on 'saving' Nightmare than actually noticing him as him so he mistakes his eyes for a green color, and when he actually comes to his senses, he realizes it was actually purple, the old nightmare was always been there ^^)