on a slighly less serious note, the colour green makes me feel good. So does sky blue colour.
A long time ago a new neighbour of mine in Melbourne painted the inside walls of his house bright yellow !! It was a very stromng colour, would have driven me crazy living inside such a house.
I painted my bedroom walls and ceiling light green (supposedly a cleansing colour), my loungeroom walls and ceiling sky blue, my study purple (don't think purple is the right description, but it is a spiritual colour).
