Sorry to burst your bubble, but there's no such thing as "haze" or "blueberry". There are so many dealers around here that try to sell that shit for like $45-50 per 1/8oz. Weed that is "haze" gets it's colour from curing for certain periods of time. Let's say you have a sativa plant (which buds plenty, but slowly) that you've been growing for a while. As the plant progresses, the mature buds just really sit on the bottom of the plant while the rest grows. It changes colour if it sits around in the already-mature state.
There are certain kinds of weed with interesting colours, but for the most part they aren't by default that certain colour. My brother had some stuff that came out of an indoor garden in New York. It had white and yellow hair, which I hadn't seen in a while. I myself actually got some excellent indoor bud the other day which appears to be of Canadian descent. For all of you guys who buy, watch out for stuff laced with formaldehyde. I've seen a ton of it around here, and my friends around the country say it's starting to emerge in a lot of cities. If your weed has a funky stench to it, sort of falls apart in your hand, has an un-natural blue/dark green colour in patches, than you have some laced stuff.
In Amsterdam they carry all sorts of shit. Northern Lights comes around here from Vermont once in a while, but most of our grass is out of New York. I wish we had more designer pot...
edit: lots of guys spray their shit with strawberry/blueberry/etc scented air fresheners and try to colour it with dyes. Fuck that... some people make me sick. The key is to know your grass so you don't get ripped off and so you don't hurt yourself.