Welcome to tPF!!!! Honestly, I've been contemplating over this one myself, as well. I know some people either prefer one hw over the other, which makes life a whole lot easier. But as for me, there are certain colors that I much prefer PHW and others with GHW and a few that I don't mind either way. Orange is one that I'm still indecisive bc Orange is one of those colors what looks great with both hw. One thing that you may want to consider is whether you would wear yellow or white gold while carrying the bag. With this in mind, I'll jump on it if I see a 30 cm Swift Birkin w/PHW.
IMO: Warm colors (orange, potiron, gold, soleil, etc) look great with GHW and Cool colors (raisin, prune, violet, fuschia, blues...) look great with PHW. Just my thoughts... Whatever you decide, let us know!
Another vote for palladium. I use orange as a spring/summer bag and I think that the PHW cools down the orange. I usually wear orange with whites, taupes and light khakis and the PHW just seems to compliment these colours better.
HOWEVER, I think that orange with GHW works better for fall/winter than with PHW. I guess I'm saying, depends on how you plan on wearing the bag.
I voted for palladium too. I've seen the bag IRL with both, and like others said here H Orange works with both. I just happen to think the palladium looked ever so slightly more 'cool' and juicy (don't even ask me why)
And I usually like the gold HW better. Make that nearly always so even I'm surprised