Depends on the comment. Something obviously like a change in hair color might draw the attention of even normally clueless guys if she's someone he would even casually notice.
On the other hand, guys have had generations of movies and sit-coms drilling into our heads the idea that:
A) Girls like it when you notice them changing stuff about their appearance.
B) Girls might also get angry and think you're insensitive if you can't answer the old romantic comedy question, "Notice anything different about me?" (Or the classic, "You don't like it?")
So, we're taught that commenting on someone's hair and clothes is a good way to look like you notice and care. He could be deliberately pointing it out as a way of flirting, or he could just be the type of compliment people when they change styles or do something bold; or he could be the type to notice, say something neutral in observation, and then make sure to turn it into nice to avoid offending.
In other words, I couldn't tell you, but it's probably somewhere from a neutral to a positive sign. It all depends on presentation, really.
That depends on if you think the guy is serious or not and if your a girl you think he'd consider being with. If yes to both of these, then yes it does have a deeper meaning. It means that he not only notices when you change hair color he also notices your hair styles, your clothes, your figure, when you talk, etc. Like he pays attention to you because he finds you as a person that's pleasing to him. It could be a little or a lot. There's so many things that people do that most other people could care less about, so when someone actually takes the time to notice and then say something, that's because they're interested in that person, as a friend, best friend or in this case even a maybe "wishful thinking" girlfriend.
i would definately notice... that has happened all the time with me you get back to school after holidays and this chick has a new hairstyle/color and I'm like, WOW! , she actually looks pretty good lol... and I'm sure that a lot of other guys would do the same thing... so yeh, they sure do notice any change you make I suppose
If you've never seen this guy in your life. I would start carrying around mace.
If it's some guy in your class you see around but don't really talk to or say hello to thennn. Unless you shaved all your hair off or dyed it blue. it may have some meaning, or he's just being nice :T
If it's a friend or some guy you say Hello to every now and then, then he's just noticing. probably because for guys, whenever they get a hair cut, it's always a DRASTIC change so the first thing they want to hear is "IT LOOKS GOOD" and when nobody says anything they'll be like "OMFG. I'M UGLY!" :T So since they know how it feels to not get noticed, they do you a favor, and notice! xDD