To be honest, I don't particularly like any of them. Rust Orange is the best of a bad lot, but it doesn't seem right for this batch of episodes.
The arrival of the Freak calls for a tough colour - a steely grey or a cold blue. And IIRC, Marie Winter is still present at the start of this volume, and similar colours suit her down to the ground. So Duck-Egg Blue feels appropriate - the shade, if not the name. And we haven't had blue since Vol. 2, of course.
But please, let's have some bolder and more vibrant choices for the next couple of volumes! A navy blue would be good around now - put a white outline around it and it'll show up nicely against the black background.