I'm still only beginning to venture into the world of matcha, and so far I've only had matcha from Enjoying Tea, and now from In Pursuit of Tea. I've heard that you can't really reproduce or find in the States the matcha quality that you'd find in Japan, and right now I'm fine with that, but I do want to get the best quality I can find.
The matcha powder I got from Enjoying Tea was a dull green, with a distinctively sweet vegetal taste remniscient of other Japanese green teas I've had, but smoother.
When I opened my matcha powder from In Pursuit of Tea yesterday, I was surprised that the color was a bright, bright green, and the taste was SO smooth and sweet that it almost tasted milky, hardly like green tea at all and not particularly vegetal. I liked the result, but in a very different way than I liked the other matcha.
What could the reason be for this variation? And should I assume that In Pursuit of Tea's matcha uses color enhancement? I'm just not even sure anymore that I even know what matcha should taste like...
the matcha i had has been at japanese tea ceremony. .... and... um... well.... not pleasant 
if you are having matcha that is pleasant i would question it ... a lot. matcha as in tea ceremony is not supposed to be pleasant, but you have a sweet treat with it and they do go well together. i would never have just matcha without the treat, nor would i have anything that was sweet or pleasant. its supposed to be bitter and unpleasant, but rewarding, there is something and enjoyable and good about it. 
i do think the matcha i had in japan was particularly special (in that bitter good kind of way) and the only thing i have had like it in america has been at tea ceremonies. if you are seeking it out have you considered tracking down people who do formal japanese tea ceremony and find out where they get their tea from??
if you are having matcha that is pleasant i would question it ... a lot. matcha as in tea ceremony is not supposed to be pleasant, but you have a sweet treat with it and they do go well together. i would never have just matcha without the treat, nor would i have anything that was sweet or pleasant. its supposed to be bitter and unpleasant, but rewarding, there is something and enjoyable and good about it. i do think the matcha i had in japan was particularly special (in that bitter good kind of way) and the only thing i have had like it in america has been at tea ceremonies. if you are seeking it out have you considered tracking down people who do formal japanese tea ceremony and find out where they get their tea from??