Which of the following is NOT included in natural hair care services?

Natural hair care services primarily focus on techniques and practices that promote the health and appearance of hair without the use of chemical treatments common in traditional hair care. Among the options provided, hair coloring stands out as a service that typically involves chemical processes to alter the hair's pigmentation.

Natural hair styling, washing and conditioning, and hair straightening (when done using heat or other non-chemical means) can be part of a natural hair care regimen. However, hair coloring generally utilizes dyes and chemicals, which do not align with the ethos of natural hair care that emphasizes the use of more organic and less processed methods.

In this context, the choice regarding hair coloring reflects a deviation from the natural hair care approach, making it distinct from the other services that support the maintenance and styling of natural hair without chemical alteration.