I don't know if men are different to women with this but what do you do if a friend asks your honest opinion on something and you know they won't like your answer. For example a friend of mine has always had the same hairstyle, and out of the blue she fancied a change and had it cut short and had bright blonde streaks put in. It didn't suit her at all. She sent me a photo of it and said her kids kept laughing at her and what did I think? I said that it was different and would take some getting used to as I didn't have the heart to say it looked awful.
So how honest are you with friends or do you just say nice things not to upset them?
I would probably say what you did, I wouldn't want to upset a friend. On the other hand I wouldn't want them to think I really liked something when I didn't.
I would give an honest opinion since they asked. If they just turned up with it and didn't bring up the subject, I would either tell them I liked it or make no comment about it. The exception is with my wife; if she dresses to go somewhere and doesn't look right, I tell her.
Some constructive and positive contribution would be tactful. Like "I always liked you old style best" or "Why don't we look in some style magazines and I could pick out some which I think would really flatter you ?"