Although people often have slightly different shades of color to their lips, which can be individual variations, it is never normal for the lips to be frankly blue in color. When this occurs, it is called cyanosis, and it reflects a state in which the blood flowing through the lips has been stripped significantly of oxygen. Blood that is not well oxygenated turns blue in color.
There are many potential causes for cyanosis, many of them being quite serious. Therefore, if you are really having a bluish color to your lips, you will need to go see your primary care doctor
as soon as possible. They will do a thorough examination looking for any signs of heart or lung disease. They will also likely want to perform some basic blood tests.
Make sure to mention to your doctor if you are experiencing any other concerning symptoms, such as shortness of breath, palpitations, chest pain, trouble with exercise, swelling in the ankles, cough or trouble lying flat at night, as these symptoms will help clue them in as to potential serious causes.
Get in to see your primary care doctor as soon as you can!