Either they are colourblind or very deep - as a poet said:

" Talkhi-e-gham na chalk jai in ankhon say kaheen.
Muskuratay hain yehi raz chupanay kay leay.

Without these moods the life will be meaningless, unless u have the ups n downs u will not enjoy the life. You have to choose the colours to fill your life. The more colour n shades u have the more you enjoy. With one one shade it will be too monotonous.

Colour is an indicator of mood n intensity, blue is sad, but you indulge in it, black is something that u never would like to have it again, orange is lively, red is something to take away with you.

yaadian can be of any colour, blue, black, orange, red. That is what the life is made of. If they did not have the colour you could never distinguish among them. Its good to live with them