Hi Janaki! I must have been busy when I read your post last time! Cutiepie alerted me to your post!
I'm thinking that you're not associating a colour with an object in your dream because you're not a 'visual' person. Do you think this is true? During a hypnotherapy class I took we were taught that there are two kinds of people: visual people & imaginative people. Maybe you are less visual (how are you at pictionary?? ha! A friend of mine isn't visual at all - we discovered! - as she sat for minutes on end unable to begin to draw a bicycle. Finally she started drawing and she drew it with four wheels and from two different angles at once! Top view and side view! Of course we all thought it was hilarious...aw.) Anyway..you may be better at pictionary that she! But maybe you are more 'imaginative' which means that you get flowing impressions (like seeing with your minds eye not your eye-eyes) or thought forms. More musical, poetic people have this sort of thing.