Hi,
Yes Vishuddha is a very pure, creative, and immensely open chakra—note the 16 vowels thereon which all equal 0 (vowels always connote creative openess, of speech too). I attribute it very much to green and the universal goddess (I associate D = 4 = Venus to it, which is also the vesica). The communication you mention as the throat chakra is interesting in light of Binah being silence and understanding, the "voice in the silence," which parallels Anahata as the "unstruck sound." These are obviously symbolic aspects of gnosis vibrating deep within the Self.
I love the Sri yantra too, and have created a few large canvases depicting it. I have one up here:
http://www.flickr.com/photos/waltdelong/page4/