IME if you've got a bit of a stomach that projects forward them straight pleats just sit like some weird peplum from the devil that screams look at my fat pockets, it's about as unflattering as it gets. I find if they're stitched diagonally, or rather the fabric is folded in diagonally, it can be flattering. In the main I tend to avoid them though as peplum from the devil can really be a bit of a confrontation with yourself, even if it is a weird distortion.
I suppose the tonal looks are a bit of an evolved take on matchy matchy. I find it hard to find things in the same undertone and colour family without having to resort to bloating out my closet for the cause and I believe matchy matchy was always a marketing strategy to get you to buy more, so in that it's quite similar. I do think those old rules of never black and blue, green and blue, etc. had relevance at the time, you simply didn't get the choice in a single colour as you do now, it was just an industry standard efficient colour and a small variation thereof, where now many will have been developed to suit several skin tones rather than just a particular undertone and choice is endless.
Genuine question, Flo, if you don't speak a word of Polish, how are you so convinced it's Polish? I've been having odd dreams for months now. I'm very much convinced they're all dreams meant for other people, completely alien environment, languages, imagery, etc. I don't even feel like me as the person experiencing the dream, very odd.