ForeFlight displays weather conditions in color coded format in relation to Flight Categories.   The following are what the colors of the Flight Category icons mean:

O Green: VFR (Visual Flight Rules) where the ceiling is greater than 3,000 feet AGL and the visibility is greater than 5 miles.

O Blue: MVFR (Marginal Visual Flight Rules) where the ceiling is between 1,000 and 3,000 feet AGL and/or the visibility is between 3 and 5 miles.

O Red: IFR (Instrument Flight Rules) where the ceiling is between 500 and 1,000 feet AGL and/or the visibility is between 1 and 3 miles.

O Magenta: LIFR (Low Instrument Flight Rules) where the ceiling is below 500 feet AGL and/or the visibility is less than 1 mile.

O Gray: The flight rules condition is unknown.

Image 1. Flight Categories on the Maps page.

 

Image 2. Flight Categories on the Airports page.