Day 27: Can You Read It?

Accessible colour means enough contrast between text and background for people with low vision, colour blindness or a bright phone screen in sunlight. The WCAG guidelines recommend a contrast ratio of at least 4.5:1 for small text and 3:1 for large text. Good contrast is not boring — it is a constraint that makes you smarter about colour.

Objective. Combine expressive colour with accessible text contrast.

Design a colourful poster for a public health clinic where every piece of text passes WCAG AA contrast.

• Check every text–background pair with a contrast checker
• Small text at least 4.5:1; large text at least 3:1
• At least three colours
• Do not default to black on white

• All text passes the required contrast ratio
• An expressive palette
• Readable at a distance

Test the poster with a deuteranopia simulator and adjust until it works there too.