What is the best basis for successful colour filling and blending?

Correct answer: A balance of paint consistency, brush control and proper timing

Successful colour filling and blending depend on coordinating three practical factors: suitable paint consistency, controlled brush movement, and correct timing between strokes or layers. The right balance produces even coverage and smooth transitions, so option B is correct. Expensive materials do not replace technique; speed alone reduces control, and excess water may cause runs, weak colour, or unwanted edges. The needed balance can vary with the medium and surface.