What about older boys with their own ideas of what they like? I have tried to dress my 10 year old in a range of colours, deliberately avoiding the usual colours. But now there is no way he will wear 'interesting' colours for the sake of it.
Both he and I share common ground.He likes skateblardy stuff and so do I (not all but some). IMO it's a bit more varied than sports style clothing, the only main alternative around here. Also, because he is not that sporty, but actually does like skatboarding, it is more true to his personality. Now Hennes do lots of quite nice skateboard stuff but will my son have any of it? no! he thinks it's an uncool label. I would say that's because Hennes do baby and girl's clothes too, but that's can't be it as my son likes (some) Gap clothes. He doesn't care if the clothes are cheap - we go to TKMaxx - but he does care that the label is not childish. He likes quicksilver, kangaroopoo, ripcurl etc. Even if Adams did the coolist looking dude stateboard stuff, and I loved it to bits, I doubt that my son would wear it.
Up until the age of 7 or 8 I could get my son into interesting things of my choice, but since then, no way, ie GAP did some lovely boys stripey jumpers at christmas but my son hated them.
IME, you can't assume a 10 year old will be as easy to dress adventurously as a 6 year old, posing problems for desingers of older boys ranges. If I was designing for my son, I think I'd look at cool adult clothing, accessories and equipment ranges (not high fashion necessarily) and possibly cool films, cartoons and personalities and base designs around these things. My son is quite into some of the Beckham range of clothing by Marks and Spencers for instance, but a single piece woudn't go with his stuff so as yet we haven't got any. I don't like the limited colours of the range, but it's interesting to note that Beckham clothing or cartoon pajamas are the only M and S clothing lines my son would wear apart from school uniform, which bears out my theory.
My prize for the worst item of boys clothing has to go to boden. A few years ago they did a stripey sleepsuit in pale blue and white. Yes an all in one sleepsuit. It was available for boys up to 12 years old!!!