Because we paint what we think and the intrest towards that art make it beautiful. The different colors defines about different emotions we have in life. Choose the right color(emotions) to make the painting(life) beautiful and interesting.
Don't deny the signs, energy and vibes you feel about some people and at some situations. Because words may go wrong but vibes don't lie. If you feel it is not right. It's not right.
When some one gives you respect, respect them back. When some one loves you, love them back. But if some one betrays you, don't betray them back. Karma will do it for you.