I personally would opt not to have another color name, unless you are sure you will only be having two kids. I can’t imagine it would be easy to continue that trend! If you want to do a color, I would suggest putting it in the middle name spot.
From your girls list, I like [name]Ivy[/name] (a color, I know, but a plant first).
I would disqualify [name]Maisie[/name] and [name]Sadie[/name] from the running since they have the same internal “a” sound as [name]Grey[/name]. Same goes for [name]Angus[/name].
I love [name]Hugo[/name] and [name]Perrin[/name] too! (I personally voted for [name]Ivy[/name] and [name]Hugo[/name], but [name]Perrin[/name] was right up there!)
[name]Opal[/name] is so-so for me.
I’m not sure how to pronounce [name]Leith[/name]? LAYth? I love the name [name]Leif[/name] (pronounced as LAYf), but again the long “a” sound is too similar to [name]Grey[/name].