Non-desert, snow free land usually appears reddish brown (terra-cotta) in the HRV Fog RGB images. The brightness of the colour strongly depends on the (solar and satellite) viewing angles; see the images below.
Meteosat, SEVIRI HRV Fog RGB images for 12 March 2014, 07:55 UTC (left) and 13 March 2014, 11:40 UTC (right)
Meteosat, SEVIRI HRV Fog RGB images for 28 November 2013, 07:40 UTC (left) and 08 January 2014, 11:10 UTC (right)
Explanation of the colours of non deserted, snow free land (see the recipe):
• The reflectivity is less then medium in the NIR1.6 channel. After the linear stretching it is around medium.
• The reflectivity value is considerably less than medium in the HRV channel.
• Both the NIR1.6 and the HRV reflectivity values depend on the surface type, and considerably depend on the viewing angles. For lower solar elevations the reflectivity values are lower.
As a consequence the red signal is higher than the (equal) green and blue signals resulting reddish brown colour; brighter at midday and darker at low solar elevation.