Don’t try be too fancy when keeping colors for a portrait
In general, portraits look unattractive and disarray if they have too many colors. You should always use a simple color combination for portraiture if you really need to keep it attractive. It is always better to leave the background with a really simple, less confusing color combination. However, you should focus more on the clothing of the subject and match it with the original skin tone.
No matter how creative you are and how expensive the equipment you use, you must not exceed three primary colors when it comes to professional portraiture. To accomplish the best, you will need to work more with hue/saturation levels using your image processing software. In other words, a nice portrait requires some processing work to get its best appearance in addition to your photographic skills.