Different colors express different moods, for example we often associate red with anger, blue with sadness. So the color can affect the mood set for you artwork. Also, in like abstract drawings it can help you because we often associate colors with certain landscapes.
According to my research on different art techniques, I can say that based on the information provided within the question many artists use vertical text or information in order to guide the viewers eyes from the top of the art piece towards the bottom. Therefore we can say that this is what the artist is doing in this situation.
I hope this answered your question. If you have any more questions feel free to ask away at Brainly.
