This is most commonly referred to as highlights, lowlights, and dimensional colors. This service can vary from an hour to several hours. Highlights on short to medium hair with one color that create a "natural look" are often done in an hour. Foil placements throughout the top of the head with multiple colors on short to medium lengths generally require 1 1/2 hours. A full head of foil placements generally requires 2 hours. Longer hair may require more time.