Marconius 2 points 2y ago
Way too vague here. Can you be more specific? While branding icons aren't subject to WCAG contrast ratios, icons and user controls within an app need to be at least 4.5:1 when compared to the background color they are on, adjacent icons, and surrounding text. Larger graphics need to have at least a 3:1 contrast ratio.
Other than that, it's just a good idea to make intuitive and understandable graphics that are relevant for the icon's purpose. That's a design call along with listening to user experience research for whatever app or product you are working on.