I don't think you should change the way you dress!
That said, I agree with others in that this may be a case of situationally appropriate, or something like a job interview, even though it really shouldn't be like that all.
All of the date night outfits I've seen you post have been FAB, and you're on the right track, as far as I'm concerned. Just beautiful and you have nothing to worry about on this front!
Not sure if this helps, but I like to cook - and sometimes I cook some weird things. Things other people might think were totally bonkers. That said, I am not going to take grilled octopus with blueberry compote to a dinner party when meeting new friends or family members of significant other. I'll 'tone it down' a wee bit so that everyone can enjoy - and even if my 'toned down' is still a little out there at times, it's still a good conversation piece.
I also like what others have said about being accessible, as well as showing off *you* so that your fabulous style doesn't obscure how beautiful you are. It's just like what they all say in terms of interview advice - allow yourself to shine so that the first thing people see is you, and not necessarily the outfit you put together, if that makes sense.
No need to change your style at all - but it is possible that your amazing style might be a tad bit intimidating at first. Like me showing up with octopus and blueberries - when I could have come up with something that everyone knows and likes (ie. macaroni and cheese) but with a totally new and fab twist. Maybe I make my mac & cheese with sundried tomatoes, pancetta bacon bits, shredded spinach and four kinds of gourmet cheese.
Come to think of it - this reminds me of Angie's outfit blog post today - a pencil skirt and blouse, and yet her pencil skirt and blouse are amazing. Anyone meeting her would immediately know there was something different and very special about her.
I see you the same way. Your "toned down" outfits are so spectacularly fab that a person couldn't fail to notice that you are someone special.
I guess this is my very long-winded way of saying that even if you did change up your date outfits a wee bit, they are still going to be *amazing*. It's kind of tough to hide your light, even if you try to.
You could wear a potato sack and look glamorous. This is just part of who you are.
I can't make ordinary macaroni and cheese - I'm always going to sneak in some asiago (or feta even), some sun-dried tomatoes or what have you.
You're the same way. A pair of jeans and a button-down shirt are going to look extra-fab on you, because you have incredible style and there isn't going to be any "going back" if that makes sense.
So, if you decided to keep on with the so-called "toned down" outfits for date-nights, never fear - your 'toned down' is still going to be kock-your-socks-off fabulous. You won't lose anything - because this incredible style that you have cannot be hidden, no matter how hard you try. You're not hiding yourself or "dialing back" in any way - you're just showing up as your fabulous self in a slightly more accessible way (at first )
Hope this wasn't too long, and more importantly - that it made some kind of sense.