Colour psychology: what the research supports and what it doesn’t

Claim 1: “62 to 90 percent of a snap judgment is colour”

The figure comes from a review article by Satyendra Singh in Management Decision. Its abstract says people make up their minds “within 90 seconds” of first meeting a person or product, and that “about 62-90 percent” of the assessment is based on colour alone.

Look at what that is. It is a literature review, and the abstract gives a range with no study named. We could read the abstract but not the body, so we cannot tell you which studies the range rests on. The same abstract says the article identifies “inconsistencies and controversies” in marketing colour psychology. Treat the figure as an unverified headline, not as a measured effect on a store.

Claim 2: “Red buttons convert better”

The claim is often traced to red-versus-green button tests. We could not open the original write-ups, so we do not repeat any numbers. What we can say:

• We found no published data behind the claim that we could check.
• The explanation commonly offered is contrast: a button stands out against what surrounds it. We found this only in practitioner commentary, such as one article arguing that “what matters is contrast with the surrounding context, not the color itself.” That article cites no data, so read it as opinion.
• Contrast with the surroundings has a better-documented psychological basis than the colour itself. Hedwig von Restorff’s early work, summarized on Laws of UX, found that the item that differs from the rest of a list is the one most likely to be remembered. The same page warns that too many highlighted elements compete with each other.

Even so, we found no checkable evidence that any one button colour wins on every store.

What the research does support

Andrew Elliot’s review limited its table of empirical effects to those supported by at least five independent laboratories. The ones in the summary we read:

• Viewing red before a challenging cognitive task has been shown to undermine performance.
• Red stimuli get an attentional advantage.
• Blue light increases subjective alertness.

Elliot lists some of these alongside studies that did not support them. And these are lab effects on things like test performance, attention and alertness. None of the effects we read concerns which colour of button a shopper clicks.

Elliot’s own conclusions are modest. He calls theory in the area “nascent”, warns that all colour effects “depend on certain conditions”, and notes that small studies often overestimate effects. He also warns that colour findings “can be provocative and media friendly.”

What to do this week

1. Check how your main add-to-cart button stands apart from the area around it. WCAG 2.2 (1.4.11) asks for at least 3:1 against adjacent colours when the button’s edge or fill is the only thing that shows it is a control. A button with readable text does not strictly need it, but the contrast is also what makes it stand out. See “Contrast is a number”.
2. Make one action the most visible on each page. If three buttons shout, none does.
3. Do not spend your first test on button colour. Test an offer, a price display or a product page change before a hue.
4. If you do test colour, change one thing, run it long enough, and treat a very large lift as a reason to check your tracking.