If a red watercolour looks less intense than expected after drying, what is the most controlled correction?

Correct answer: Increase a little base red and test a new dry sample

Watercolour often appears lighter or less saturated after the water evaporates, so correction should be gradual and tested after drying. Adding a small amount of the same base red increases pigment concentration while preserving the intended hue. Option C is correct. More water weakens the colour, green is complementary and can dull red, and black lowers value rather than restoring clean saturation. A dry sample confirms the final result.