Changes in color of the skin and systemic disease.

When looking for diseases of the skin, this is usually done in a holistic way, automatically and unconsciously, by recognizing localization, distribution, and appearance of the primary or secondary skin lesions. When Robert Willan (1757-1812) introduced the concept of morphology of skin lesions, it became the basis for the classification of dermatoses. Apart from ethnic factors, the various dermatoses comprise a rainbow of colors ranging from the most common red color to yellow, blue, brown, silver, green, black, and white.