Let me start with a couple examples. A female coworker recently showed up at the office with short hair. Whereas previously it had been mid-back length, she’d cut it to be only a few inches long. It looked OK at best; but she looked significantly worse than she had with long hair. When she walked into our area of the office for the first time, the “feedback” started…
Guy 1: “Oh, wow you cut your hair – it looks great!”
Guy 2: “Yeah, wow, looks good.”
Guy 3: “You look much younger.”(I didn’t contribute, because I’d run into her earlier in the day and after expressing my surprise at barely recognizing her, told her it looked “stylish” in an unenthusiastic tone.)
When she walked out of our area and out of earshot, we all looked at each other. Guy 1, who had previously always talked about how sexy this girl was, burst out immediately: “Maaann, it looks horrible! What did she do???” We all agreed.
Another time, a girl walked into the same area of our office wearing a new shirt, which was bright green. It drew attention, but it looked horrible. It didn't work with her complexion at all. Immediately, one guy – who is particularly attractive to most of the girls in the office – said “Nice shirt. Good color; green looks good on you.” I am sure she walked away thinking to herself “Wow, I guess green is my color.”
In the first example, obviously the intention behind the compliment was to make the cute girl feel good, or at least to avoid making her feel bad. This is fairly easy to recognize and understand. But something different is at work in the second example, and I've been recognizing it happening more and more in my daily life as I've come to realize what is going on: people respond positively to the things they notice, not to things that are positive. A person might see a friend and think “wow look at that new belt” because it really stands out, or “wow her hairstyle (or color) is completely different today.” But then, because it is so noticeable, they feel the need to acknowledge it. Once they've acknowledged it, the same phenomenon at work in the first example kicks in: they feel the need to make the person feel good about it, and an inaccurate compliment is the result. So in the end, “nice haircut” actually just means “I noticed your haircut.” And if you subscribe to the school of style that says "you should wear your clothes; your clothes shouldn't wear you," then you realize that this is more often a bad sign than a good one.
I've occasionally been given compliments like "you look good in grey." However, knowing what I do about wearing colors that compliment my complexion (I look OK in grey, but not great. I wear grey because it is an easy color to find in stores and doesn't look horrible on me), and recognizing that these compliments came from someone with the desire to make me feel good, I realize that what they really meant was "You look good," and "you wear a lot of grey." But the causal link between those two facts what purely in the eye of the beholder - or rather, the complimenter.
But the problem isn't only that people get inaccurate feedback when they wear or change things in extreme or otherwise noticeable ways. The problem is that when people change things in subtle-yet-powerful ways, they get no feedback whatsoever. The best changes more often than not draw no feedback, while the worst changes draw compliments. If you pay attention to others’ opinions, you’ll end up with a completely skewed opinion of what makes you look good.
The best compliments are those that are mistaken, or indefinite. I've had this happen to me several times. One time my receptionist told me “Andrew, you look great today! Did you change your hair?” I hadn't touched it. In fact, nothing was different about me that day except for my shirt. It happened to be one that I didn't normally wear, but which, in retrospect, perfectly complemented my complexion. Her compliment of my hair was actually a compliment of my shirt.
So pay attention when people give you general or indefinite compliments: “you look very… vibrant today,” or “something looks different; I like it,” or “did you change your hair?” (even though you haven’t). If you reflect when you receive compliments like this, you can often decipher them to understand their source. And if you succeed, you can rely on your interpretation of that vague or mistaken compliment far more than you can rely on normal “compliments,” which are often little more than sugar-coated observations.