Just like a rainbow of many colors. As long and you put into consideration properly the principles of art. Producing an art piece won't be an issue.
How about understanding of light and shade. You need to understand your color and application of the colors is essential too.
Here is a portrait of a beautiful young damsel. It's a quick one and I have used variety of colors.
Below are stages of my drawings
Thanks for constantly checking and voting my drawings. Thank you.