Contrast is hugely important in creating emotion.
Watching a bald Lady Gaga with a piano covered in hair - creates ideas, thinking, emotions in the audience. It strengthened the words in the song, it gave visual memory as well as audible.
Marketing can also benefit from using contrast. Contrast in terms of stories, colour etc but also in how you convey the message.
A message which balances the contrast can be so more powerful - for example, health issues caused by obesity followed by the hope of losing the weight.
The important bit is that the contrast comes to stir emotion not in illustrating inconsistency in your brand values. The contrast of what you say and what you deliver is not stirring the right emotion from the customer!
The question is
Do you convey a straightforward message or do you use contrast to create a greater impact?