Images and Colours

Images

Images convey information, illustrate text content, and create impressions. They often support understanding and thus improve accessibility. However, images can also reduce accessibility if the information they contain is available only in visual form.

From an accessibility perspective, the key is to provide an alt text (alternative text). Alt text describes what the image shows or communicates in its context. It is also known as alternative description, text alternative, or alt text. How to add alt text varies depending on the publishing platform. Usually, it can be found by editing the image and its properties in the page’s editing mode.

Colours

Visual design is an essential part of a functional and pleasant online service. From an accessibility perspective, colour use should follow three core principles:

• Text and background must have sufficient contrast.
• Colour alone must not be used to convey meaning or functions.
• Colour choices must not prevent, for example, people with colour blindness or low vision from accessing information.

Below are examples illustrating how contrast affects text readability. Consider:

• Do you notice differences in readability?
• Why is some text easier to read than others?
• How can readability be improved?