The meanings are very close, with nenávidět being perhaps stronger (especially, I think, when used about people). But both are accepted for this sentence.
"When a coffee is described as light, it simply means the beans have been roasted less. Beans that are roasted more are often darker. Light coffee typically packs a punch..."
There used to be but was lost. Now we just have the negative variant and no standard way of directly negating that. It is a recognized language deficiency in Czech.