Color alone is used to indicate meaning or convey information.
Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element.
- If a button is greyed-out to indicate action is required before activating the button, that should not be done only by the color of the button.
- If input in a text entry field is required with a red asterisk, also use the word "Required" in or near that form field, as well as with initial instructions to user on the page.
- If data is presented in a complex graphic that relies on color to differentiate between elements, use clear labels, or present that data in a table or another format with the visual representation.