The line will tell you what you are looking at most of the time. every once in a while I do achieve the explanation through line but it is harder. To our mind it is unnatural and so it is abstract. Our left side of the brain takes over and tries to assign meaning to it. Tell us what we are looking at.
On the other hand we have seen color since our first sight. When we are young our right side rules and we assign emotions to them - Red(hot), Blue(cool), White(soft) and so on. It becomes a big jumble in us even when the left side of the brain takes over. Color still defines how we feel.
When I took the number 5 bus from work to downtown late at night I had to walk(very fast) 45 minutes to get to the bus. So usually I would get there minutes before it left. It had a 15 minute layover there. I got there with 2 to 3 minutes left. On this night I got a ride to the stop. So I was there before it even got there. Having 15 minutes to wait I decided to draw this. Dark on and off the bus, it was a bit moody. Nobody else on the bus talked we just sat there waiting and relaxing. Out the window the street lights threw yellow spots on the empty parking lot - inside the driver was quietly reading her paper.
This is an example of just a little color makes the image POP. most of the colors during winter are bleak. We bundle up like mummy's to stay warm as we go about. This guy was humming a happy tune. Don't remember it now but his attitude was infectious. The line drawing did not do him justice so I added the tiny splash of color to his face. A stark contrast in the dark grey hood and color of his face.