Preventing Backgrounds from Obscuring Text

Text drawn over a varied background, such as a wash of colors or a bitmap, may be illegible for some viewers, so you should always provide the user with the option to omit the image and revert to a plain background. Text is most legible when drawn against a plain background of a contrasting color, and many users with low vision will not be able to read text if the background is irregular.

Instead of providing an option to control contrast in your application, you can simply omit the background in response to the High Contrast Mode setting, which is discussed in the following section. You should also omit the background if the foreground color changes. For example, text drawn over a very light bitmap image might appear quite legible in the default color scheme, but be unreadable if the user chooses a light foreground text color.

You can keep a complex background reasonably legible by making sure that the background image contrasts well with the text. If the foreground text is black, many users will find it hard to read if it is drawn over areas of the image that are brown or other dark colors.