Earlier TV's would be black and white. As technology advanced, TV's became colour. Our visual experience was more satisfying with colour TV's. Colour added vibrancy to the viewership. So is the case with life. A dull life has no excitement, no colour. It is boring, monotonous.
A spirit which is alive, beats with an exciting heart beat. A lively person is often a lovely person. The life he emits exhibits his inner positivity. He feels excited at small things like a little child, and when hurdles come his way he has the energy to overcome them. Energy is colour. Energy is innocent. Energy can be active or passive. Even a silent person feeling inner peace has internal energy in him. Energy is colour, colour is energy.
Colour does not mean to be immoral. Colour means to feel joy, experience peace, feel free, and have fun. Only those experiencing peace can have fun. Fun is not immoral. Fun is the natural joy felt at the present moment. Fun does not need external stimuli to present to be enjoyed. Fun can be a state of internal joy. So, when we talk to colour, we talk of fun, joy, and peace. This is infact is the aim of human existence - a life of colours.
Happy Holi !