Answer:
The prediction that "bright colors will make people happier" is called a(n) hypothesis
Step-by-step explanation:
A hypothesis is a vague theory about something and from which the person who states it does not have any kind of factual proof or any real fundament at all, it is based in few pieces of information and it can not yet be demonstrated through viable evidence, Then it is not a 100 % sure that bright colors will make people happier.