The TomTom Danger Zones app warns you about danger zones and risk zones in the same way.
When you approach a zone, Danger Zone or Risk Zone is shown in the information bar, and the zone warning triangle is shown above the horizon:
You hear a three-chime warning sound at the start of the zone, and a two-chime warning sound at the end of the zone. The warning sound depends on your speed:
The horizon behind the warning triangle glows. The colour of the horizon also depends on your speed: