For example, your app icon would be blue and black and your logo on printed shirts would be red and black.
Think of your brand as a human. One day it behaves super nice, and one day it behaves super angry.
People don't remember shifting personalities. They remember consistent personas because they can trust them. Better trust, high recall value.
Keep the palette the same across collaterals to create an impactful persona.
Happy to answer any follow-up questions over a call. 10 years of experience in branding & UX/UI.