Happy to read your enthusiasm for this dress! Yikes, I can imagine any of them working in your wardrobe. Of course I want you to get the plaid so we could hopefully be dress twins. But I know you love red, and soft blue looks sublime on you.
That being said, the plaid would be a different color for you, I think. I’m remembering that red and soft blue are already well represented in your wardrobe.
So I’ll cast my vote for plaid.