Accessible PowerPoint (implementation guide)

1.3. Colours for conveying information

If colours are used to convey information (e.g. in diagrams or to mark text), labels, symbols or patterns convey the same information.

What is meant by this?

It is recommended that information is not only represented by colours, but also by labels, symbols or patterns. This means, for example, that colour AND pattern should be used in a diagram to represent a bar. For example, buttons in the colours green and red are also labelled with "yes" and "no". This creates opportunities to improve the perception of visual information.

Why is it important?

If information is presented exclusively through colours, recipients who do not perceive all colours clearly may have difficulty understanding this information. There is a risk that information that is only conveyed via colours will be lost on such groups of people. For example, recipients with colour vision deficiency have difficulties perceiving certain colours or contrasts. Colours with the same saturation can prevent full perception of what is shown and result in not all information being absorbed. Grey contrasts should also only be used to a limited extent, as recipients with colour vision problems may have difficulty recognising certain shades of grey or differences in brightness.

Through the additional use of labels, symbols or patterns, information can be presented in several ways to ensure that it is also accessible to groups of people who work independently of the colour display, are distracted by bright colours or perceive stimuli very strongly.

How can I implement/check it?

There are different procedures for Mac and Windows operating systems for implementation and testing:

For example, to add a pattern to a diagram in PowerPoint, you can proceed as follows:

For Mac:

1. Click on the diagram to select it. A frame should now appear around the diagram.
2. Click on the area of the diagram that is to contain a (different) colour and a pattern.
3. Right-click to open a pop-up menu. Select "Format data series". A window appears on the right-hand side.
4. Under "Filling", select a strong colour under "Single-colour filling".
5. Finally, under "Pattern fill", select a clearly recognisable pattern that you have not yet used in the colour combination in this diagram.

For Windows:

Click on the diagram to select it. A frame should now appear around the diagram.

Click on the "Format" tab at the top of the menu bar to display the formatting options for the chart, on the left hand side you will find a drop down menu where you can select which part of the chart you want to edit.

In the "Format" tab, you will find a button with the name "Fill effects". Click on it to open the menu for filling the diagram.

Select the "Structure" option from the "Fill effects" drop-down menu

Select a pattern by clicking on it. You can choose from a variety of patterns, including diagonal lines, dots, crosses and more.

You should also add a caption to each chart in PowerPoint and proceed as follows:

For Mac:

1. Click on Print layout in the View menu.
2. Click on the diagram and then on the Draft diagram tab.
3. Click on "Add diagram element" and then on "Data labels" and or "Axis title" and select the desired title option.
4. Select the position of the data labels here. If the data for the table is not generated, enter it manually.
5. Change the font, font size and font colour of the label by clicking on the corresponding buttons in the menu bar.
6. Position the labelling at the desired location by dragging it with the mouse.
7. Repeat this process for any other labelling you wish to add.

For Windows:

1. Click on the diagram to select it. This displays the diagram tools at the top of the menu bar.
2. Click on the "Diagram design" tab, which is located directly above the menu bar, to access the diagram tools.
3. In the "Add diagram elements" section, click on the "Data labels", "Axis title" or "Diagram title" button to display a list of labelling options.
4. Select the label you want to add.
5. Enter the text for the caption by clicking on the text field that appears on the slide.
6. Change the font, font size and font colour of the label by clicking on the corresponding buttons in the menu bar.
7. Position the labelling at the desired location by dragging it with the mouse.
8. Repeat this process for all other labels that you want to add.

Diagrams and other representations should be viewed in different ways for testing, for example by fading out colours or changing the brightness to ensure that the information is easy to understand regardless of colour. There are various ways to do this.

Print the respective slide in greyscale to get an idea of what your displays look like without colours. In addition, you can set the brightness of your end device from "very high" to "very low" and check whether the information is still accessible.