Is it permissible for a girl to apply light lipstick to conceal the darkness of her lips, which has affected her self-confidence?

If the adornment is to be displayed only in front of women, then there is no harm in it, because the original ruling is the permissibility for a woman to adorn herself, based on the Almighty’s saying: ﴿Say, "Who has forbidden the adornment of Allah which He has produced for His servants and the good things, pure and lawful, from the provision?"﴾ [Al-A'raf: 32]. Such adornment may be displayed in front of women, based on the Almighty’s saying: ﴿And not expose their adornment except to their husbands…or their women.﴾ [An-Nur: 31]. However, if the adornment is to be displayed in front of non-mahram men, then it is not permissible, because darkening the lips is not considered a defect. And it is better to wear the niqab, for it is a covering and an act of obedience, and it achieves the benefit of concealment from the gaze of observers.