Why is the Density Altitude in the METAR an orange color?

ForeFlight Mobile displays calculated density altitude information in the app under Airports > Weather > METAR. The density altitude value is usually represented in blue. However, if the density altitude surpasses the field elevation by 2500 feet or more, the value changes color to orange. This color shift serves as a visual signal for pilots to indicate the presence of a high-density altitude that demands careful aircraft performance assessment.

For example, KDYS has a field elevation of 1790 feet MSL. When looking at the METAR below, the density Altitude was calculated to be 4828 ft MSL. Since the density altitude is more than 2500 feet over the field elevation, the text color changed to orange.