Walk past a sale in Sri Lanka and you will probably see red before you see the price. That is not an accident. Red signals urgency, energy and attention. The trouble begins when every shopfront uses the same signal at the same volume. Eventually the loudest colour in the street becomes wallpaper.
Attention is only the first job
A red banner may stop someone for a second. It still has to tell them whose offer it is, why it matters and what to do next. If the brand disappears behind a giant discount, the customer remembers the price and forgets the business.
That matters even more on a phone. A feed gives each message a small piece of screen and very little time. Distinctive colour, type, imagery and tone work together. No single shade can carry the entire campaign.
Look at the whole category
Before choosing a palette, put competitor work side by side. Which visual cues are repeated so often that people may mistake one brand for another? Which cues already belong to your brand? The answer could be a colour, but it might be a photographic style, a particular shape or the way you speak.
There is nothing wrong with using red. There is something wrong with using it because everyone else is doing it. A brand can own a familiar colour when its composition and message are unmistakably its own.
Give the design a clear job
Ask what the audience needs to understand at first glance. Is the campaign introducing a product, explaining a benefit or asking for a visit? Keep that message prominent. Let the offer support it rather than swallow it.
Then review the work at the size and speed at which people will actually see it. The perfect enlarged presentation slide is a poor test of a phone screen in a crowded bus. If the brand and the point survive that test, the creative is doing useful work.