That hair needs to be styled better, or rooted better, or whatever it is that will make it look better. Right now it just looks like Natasha wearing a cheap wig. It doesn't look like it's actually her hair at all.
And actually, continuity be damned, if I don't like the final headsculpt for this I'll just buy one of those knockoff Civil War heads with the long blonde hair that you can find on ebay. I like the idea of Natasha going blonde to disguise her looks , but I never did like the short hairdo.
Here's something else I'm wondering about: could Hot Toys produce this figure with no new pieces other than the green vest? Because it looks like a standard Black Widow uniform under there. If Hot Toys doesn't give us a new headsculpt for this, it could end up being a glorified kitbash.