@Bigcat25, of course, it is all about fit, I agree. And the OP will know what colors are best for her (and it may well not be green, agreed!)
But I just can't imagine how polyester (in a dress that looks polyester from a mile away) can ever look better than silk or another natural fabric, or even a high quality viscose (which is less than ideal, yes, but is a step up from 100% polyester).
For me, if it isn't made from a natural fiber, and I can't imagine wanting to wear it for years to come, then I just don't want it and don't buy it. OP may well feel differently (but her original question was whether to splash out on silk... for me, I always think it is worth splashing out on).
I was trying to helpful in all this. I wasn't saying, "this is the dress, this green one, which isn't even in your size, particularly when the OP is tall, and likes bold patterns. But, as she asked, I was trying to explain why the details on the green dress (which we all agree isn't "the dress") might read as less fussy and less cheap...
Honestly, when other people post, "well, it's all subjective, you can't say one dress is objectively better than another," I feel confused. We all might have very different opinions on preferred colors, preferred styles and shapes, what looks best on us, but a polyester dress, poorly constructed, isn't "better" in any world, than a dress well-made constructed from silk. (And, to be frank, the original silk dress isn't that well-constructed - look at the pattern match. But it is better made, and better fabric, than the others).
At the end of the day, OP should and will wear what she likes. But it might help, say, to watch the videos made by Andrea Cheong. I don't actually like Andrea's style - her clothes wouldn't suit me, in their shape, colors, or design - BUT when she explains how clothes are made, and why they don't last and don't actually look good on, well that applies to all clothes, all colors, for all body-types, including our individual styles.
https://www.theguardian.com/fashion/article/2024/aug/15/the-care-label-queen-how-andrea-cheong-will-stop-you-buying-bad-clothes