If all colours in a picture are cool except one object in a very warm colour, how can harmony be preserved?

Correct answer: By repeating small accents of the warm colour elsewhere

Colour harmony can be preserved through colour echo: repeating a small accent of the exceptional warm colour in selected areas connects it to the rest of the picture. The warm object may remain a focal point, but the echoes prevent it from appearing completely isolated. Option C is correct. Spreading the colour equally removes hierarchy, eliminating cool colours changes the scheme, and removing the main shape avoids rather than solves the design problem.