To find insufficient color contrast, look for text in your document that’s hard to read or to distinguish from the background. If your document has a high level of contrast between text and background, more people can see and use the content.
Here are some ideas to consider:
Ensure that text displays well by using the Automatic setting for font colors.
Select your text, and then select Home > Font Color > Automatic.
Use the Colour Contrast Analyzer, a free app that analyzes colors and contrast, and displays results almost immediately.