The following guidelines address common design pitfalls when creating or editing a map style. Google recommends you also consult with a graphic designer to assemble and review your design.
Make sure there is enough color contrast: Contrast helps keep the text readable and helps distinguish certain map features. For details, see Choose contrasting fill and stroke colors.
Check different zoom levels: Test that your style elements look good at different zoom levels.
Avoid color combinations known to be problematic for colorblind users: Make sure your design is usable for people who are colorblind.
Check Night mode: For mobile designs, make sure your design works with Night mode.
Choose contrasting fill and stroke colors
Make sure there is enough contrast between fill and stroke colors to make sure your map features are distinguishable from the background and from similar map features.
Polygons for a line: Choose colors that contrast to show the detail on a line. For example, trails are dotted lines, and if the colors don't have enough contrast, it looks like a solid line. Highways are outlined on the outer edges, so without contrast, they may look solid, and therefore could be confused with other road types.
Polygons for a shape: Contrast helps you see the borders between polygons that are next to each other.
Text stroke and fill: For text, the stroke is your outline color, which helps to make the text readable against background colors. If the stroke color is too similar to the fill color, your fonts may also appear blurry or out of focus.