Yeah. [Not that he knows what it's like to be able to hide, exactly, but he can easily picture what it would be like if he could. Always wondering if they'd react the same to him if he let his real self show, afraid he'd slip up and they'd find out and he'd have to see that horrified shock.]
I told you that you don't have to be anything else with me. I meant it. [It's the absolute least he can do.] ...Unless you want to. [He does get why she'd want to be blonde around him, out of habit or any number of reasons.]
And if anyone says anything other than how pretty you are, they'd better be invulnerable to rock-punchings, fire, and lightning. [A very Lina-like thing to say, especially for one typically even-tempered about little personal slights, but whatever. They'd deserve it.]