How can you use color and typography to create a consistent UI design for product design?

While choosing the colors for the interactive components, the designers should also consider accessibility. There are certain color combinations that look delightful but are not accessible since they do not maintain the minimum required contrast of 4.5:1. [AA standard] Care must be taken while selecting the primary and secondary colors in such a way that they always maintain the required contrast ratio, thereby making the components accessible. Although the primary color represents your brand, if it does not fit the accessibility standards with the black or white text, it is a good idea to consider a different color for your UI components, like Google has all the buttons in blue.

Color: Primary Color: Main color representing your brand or app. Secondary Colors: Complementary to primary, for hover effects or secondary elements. Feedback Colors: Use colors like red for errors, green for success. Ensure Consistency: Use the same color for the same purpose throughout. Typography: Choose a Legible Font: Select one for headings and another for body text. Establish Hierarchy: Make headings, subheadings, and body text distinct in size. Ensure Contrast: Text should be easily readable against its background. Tips: Use design tools to define and reuse colors and fonts. Test designs with users and peers for feedback. Document your color and font choices for reference.

Considering the contrast ratios of the button colors with text as well as with the backgrounds, one should use the new method of APCA (Advanced perceived contrast algorithm) instead of regular contrast, which relies on the *lightness index* of color, to check if the perceived contrast qualifies with the accessibility standards. Also, while checking the buttons, for contrast, with backgrounds, care must be taken to check all the button styles, which include primary, secondary, tertiary, ghost, and disabled against all possible backgrounds colors.

It is always a good idea to have standardized methods of defining typographical hierarchy. The idea is to use only three-five font sizes, to maintain the visual hierarchy within a page. These font sizes can be labeled as titles, headings, body, or subtext. It is always helpful to define them in advance after testing the initial designs for legibility and encourage designers now to use sizes and weights other than what has already been defined in the style guide. Figma allows you to define these style guides and publish them as a system and it is encouraged to use this standardization to maintain consistency across the product.

Accessibility alert: You should also test your product with available accessibility checkers for contrast violations and missing screen reader labels. This will allow all the users, including those with disabilities to consume the content on your site or product.