If dark colour is accidentally applied to a light area, what is the safest correction while it is still wet?

Correct answer: Gently lift the colour with a clean damp brush or absorbent paper

The governing concept is wet-colour correction by lifting rather than scrubbing. While the paint remains wet, a clean slightly damp brush or absorbent paper can remove some excess pigment with light pressure and preserve the surrounding light area. Spreading enlarges the stain, black paint makes the area darker, and forceful rubbing can roughen or tear the paper surface. Therefore, gentle lifting is safest.