Colour contrast: the questions we get asked most

It comes up on almost every project, usually later than it should. The questions about colour contrast that come up most often on our calls.

Consistency is the quiet half of design work: it rarely gets complimented, and its absence is noticed immediately. If it only works because one person remembers to do something, it does not work yet.

Do we need to care about this?

Body text needs a 4.5:1 contrast ratio against its background. It is worth being explicit about, because assumptions differ quietly. The practical test is whether someone new to the project could tell, in a minute, that it had been handled.

Can it wait until after launch?

Occasionally. More often the post-launch version costs several times the pre-launch one. It is worth being explicit about, because assumptions differ quietly.

How do we know it is working?

Contrast checkers take seconds and settle arguments. It is worth being explicit about, because assumptions differ quietly. It is the sort of thing that looks like polish right up until it costs you an enquiry.

The short version

Design decisions are the ones clients feel most confident arguing about, which makes it worth separating taste from evidence early. Three things worth confirming about colour contrast before you move on:

• Someone can say what the current setup is without going to look
• Contrast checkers take seconds and settle arguments — and you know whether that is true here
• There is a way to tell whether the last change to this helped

Most of the value here comes from doing the first two things, not all of them.