Which option is suitable for a balanced colour scheme in poster colour work?

Correct answer: Limited main colours with their light and dark values

A balanced colour scheme depends on unity, controlled variety, and clear visual emphasis. Using a limited group of main colours prevents the poster from becoming confusing, while lighter and darker values create contrast and depth. Option A can make every area compete for attention, and using only black removes colour variety. Equal quantities of all colours do not necessarily create harmony. Therefore, limited colours with planned values make option B the best answer.