Actually, if you want to know, the colours red, green and yellow were the first things to perplex me, but I knew they were central. The image was appearing but I couldn't see what it was (obviously ;)) and then the 'who I am', said, "I killed someone." Not, "I am a killer" which is how I first interpreted it, hence my guess of Gavin Elster, as the colours were symbolic in Vertigo and he was a 'killer'.
Then the image was added to and the colours red, green and yellow seemed to be coming out strongly, especially where the Ruby slippers were. 'Dorothy' clicked in, and I listened to each of the tracks again and Boom! I was convinced. Red - Ruby Red slippers. Green - Emerald City. Yellow - Yellow Brick Wall. Brain - Scarecrow. Heart - Tin Man. Courage - Lion.
I'm always afraid, when I'm giving the clues that they are obvious. Too obvious. I think it's really hard to give not too easy clues, but it seems, as we all don't think alike, it's pretty easy. :D
Thanks for the explanation. Now I know I'm giving the right clues that, when you know the answer, are obvious and not misleading or wrong. :)