The problem
Melanin-rich or vascularly congested lips carry blue, grey, brown or purple tones, often unevenly (darker at the border, on the lower lip, or in smokers' patches). Lay a normal pink over that and it heals dull, grey or 'bruised'.
Complementary neutralising
Colour theory says opposite hues cancel. Blue and purple are countered with orange and warm gold; brown is countered with a lighter warm peach; grey needs warmth plus a touch of brightness. Correctors are iron-oxide-heavy, deliberately warm pigments used as a base layer.
Very dark lips may need two or three neutralising passes across separate healed sessions before any 'pretty' colour goes on. Rushing it just buries the problem.
Setting expectations
Corrected lips heal even and warmed, not bright pink. The honest before-and-after is 'patchy blue-brown' to 'uniform warm rose'. Clients who want fuchsia on a deep lip are not good candidates and should be told so at consultation.
Skill and risk
This is advanced work. Over-warming leaves an orange cast; under-warming leaves the grey showing; too many aggressive passes risk hyperpigmentation, especially in higher Fitzpatrick types. It belongs to experienced artists, not week-one graduates.
