High Contrast is a feature that heightens the color contrast of some text and images on your computer screen, making those items more distinct and easier to identify.
Open Appearance Settings by clicking the Start button and then clicking Control Panel. In the search box, type window color, and then click Change window colors and metrics.
Under Basic and High Contrast Themes, click the high-contrast color scheme that you want to use.
In the left pane, click Change color scheme.
Under Color scheme, click the high-contrast color scheme that you want to use, and then click OK.