A natural reason that a person may have darker gums that are black or dark brown is skin pigment balance. Just as skin color can vary, so can gum color. For some people, often of non-Caucasian descent, gums can have spotted darkness or may not be pink at all.
http://www.watertowerdentalcare.com/blog/food-for-thought/gum-discoloration-causes-gums-turn-black-white/
If the white areas of the gums are not limited to the edges of the teeth but are rather flat areas that cover the roof of your mouth, cheeks, or other similar areas then there are at least two possibilities.
https://www.zocdoc.com/answers/10994/why-are-my-gums-turning-white
Smokers may develop white lesions in the mouth. White gums are commonly caused by gingivitis, which can cause bad breath. Gingivitis develops from poor dental hygiene that permits bacteria to form between the teeth and at the gum line. To maintain gum health, regular brushing and flossing are essential.
http://www.wisegeek.org/what-causes-white-gums.htm
There are several potential causes of white gums. One simple cause is the collection of food and other debris along the edge of the gums where they contact they teeth.
https://www.zocdoc.com/answers/10994/why-are-my-gums-turning-white
So if you happen to notice that your gums have turned black, grey, or white, you may be quite concerned. While some gum discoloration is a natural occurrence, other discoloration can be hazardous to your health and require serious attention. Here are the main causes of and reasons for gum discoloration.
http://www.watertowerdentalcare.com/blog/food-for-thought/gum-discoloration-causes-gums-turn-black-white/
Possibilities are-: It might feel bulky because it is bulky or because the temporary crown or previous tooth was under -contoured by comparison. The gums may feel sensitive from the recent dental work, gum inflammation from poor plaque control, a bite problem, or from the crown that is irritating the gums.
https://www.healthtap.com/topics/what-do-white-gums-mean
Periodontal disease, a disorder involving bacterial infection of the gums, is very prevalent in the United States today.1 It is estimated that 35.7 million Americans are living with the disease.1 It is present when inflammation and infection destroy the tissues that support the teeth, including the gums, the periodontal ligaments, and the tooth ...
http://www.colgateprofessional.com/patient-education/articles/what-is-gingivitis
When a person have dark gums what does that mean would like to no? Dark gums?: dark like in brown would probably mean normal pigmentation and this varies from individual to individual in the same manner as skin color. dark like in red\purple would probably indicate gum inflammation and periodontal problems.
https://www.healthtap.com/topics/what-do-white-gums-mean
My gums are turning yellow, what causes this? If your gums are turning yellow or are discolored, this is an indication of a serious health issue that needs to be addressed as soon as possible. In many cases, a yellow coating on your gum line is an indication that you have begun to develop gingivitis. Plaque and tartar builds up along the gum line when you fail to follow a regular schedule of professional dental cleanings. This build up appears as a yellowish deposit along the gums.
http://www.pecanparkdental.com/gums-turning-yellow-causes/
White gums are commonly caused by the gum disease gingivitis, a yeast infection, or tobacco usage. Lesions in the mouth are frequently caused by tobacco, both smoked or chewed, and generally appear white. This deviation in gum color is also often seen in people with a compromised immune system.
http://www.wisegeek.org/what-causes-white-gums.htm
what does it mean if your gums are pale?
The meaning of  if your gums are pale it is caused by the gum disease gingivitis, a yeast infection, or tobacco usage.