A practical checklist for colour contrast

Most teams know this matters. Fewer have decided who owns it. Run through this the next time colour contrast comes up.

Consistency is the quiet half of design work: it rarely gets complimented, and its absence is noticed immediately. Write the reasoning down alongside the decision, because the reasoning is what changes first.

The checklist

• Body text needs a 4.5:1 contrast ratio against its background
• Light grey on white fails more often than designers expect
• Contrast checkers take seconds and settle arguments
• Someone is named as the owner
• There is a date to review it again

What it costs to ignore

Body text needs a 4.5:1 contrast ratio against its background. The cost of getting this wrong is rarely visible on the day it happens. The practical test is whether someone new to the project could tell, in a minute, that it had been handled.

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
• Body text needs a 4.5:1 contrast ratio against its background — and you know whether that is true here
• There is a way to tell whether the last change to this helped

None of this needs a rewrite. Most of it is a morning's work once someone decides to do it.