What effect is created by placing a red boat in a blue sea?

Correct answer: The boat will stand out because of warm-cool colour contrast

The governing concept is warm-cool contrast. Red is commonly perceived as a warm colour, whereas blue is commonly perceived as a cool colour. When the red boat is placed against the blue sea, their different temperature qualities create visual contrast, making the boat noticeable and prominent. Thus option C is correct. Option A describes blending, which is more likely when colours are similar; option B ignores the warm red, and option D incorrectly treats separate painted areas as if they were automatically mixed.