Tough call. I love the pop of colour in the heels, and you don't really get that with the cognac version the way you do in the others. But I find yellow shoes a bit difficult to wear, especially if they're chunky. I wind up feeling like a duck...
How matchy are you? Are you okay with the shoes being the only yellow (besides your blonde hair) in the outfit? I think I would need scarves etc with some yellow to feel like the colour was tied-in somehow.
I think I'm leaning towards the cognac.