I don't really like that word either: mirth
It's an old word but it also just doesn't feel right. Maybe that's because it's an old word [unused]
I don't know what to suggest though.
I also don't really like "shades of pink" especially when you use "shrill red cry" further down that same verse.
Maybe use a word to describe the feeling of a pink shade? shades of warmth, comfort, delight...
I love the entire second verse. It's fucking perfect, man, and I wouldn't change a bit of that. Except, maybe the last three lines: maybe that should be a verse of its own?
Haha, yeah love it love it, love that verse, except this bit...
The whole thing has this uncertain or unconfident [is that a fucking word?] feel. words like: alone, murmour, glass lips, melts, blurring, shudders...
I didn't know you could write poetry.
Fuck, you learn something new everyday.