From the watch face, hold , and select Watch Settings > Accessibility.

Color Filters

Sets the color mode for all screens, increasing color visibility for colorblindness. You can remove specific colors such as red, green, or blue, or select Grayscale to remove all color.

Hourly Alert

Enables an alert at the start of each hour. Your can set this alert as a watch tone or vibration, spoken time of day, or any combination.