Final answer:
A cosmetologist may apply a lighter shade of foundation during a corrective makeup service to correct uneven skin tones and to add dimension and brightness to certain areas of the face.
Step-by-step explanation:
A cosmetologist may apply a lighter shade of foundation during a corrective makeup service for several reasons. One reason is to correct uneven skin tones or to balance out any discoloration in the skin. By applying a lighter shade of foundation, the cosmetologist can create a more even and natural-looking complexion. Additionally, a lighter shade of foundation can be used to highlight certain areas of the face, adding dimension and brightness.