Tonal directions: Light
A Light dominant tonal direction is one in which the primary, most important aspect of a person's skintone, hair and eye colour is that it has a light undertone, and needs lighter colours to look its best. Their hair will be fair - light brown, blonde, white or grey, and their eyes light in colour. A Light dominant person might be either a Spring or a Summer in seasonal palette terms, depending on their secondary tonal direction, as illustrated below.
As you can see, the tonal direction Light always translates to either a Spring or a Summer palette, as both these are typified by light colours with a good dose of white added into them. The secondary tonal direction dictates which of the two palettes it falls into