Top row: colour composite images in the H and K bands (observation taken in 2008 with the AMBER instrument, with 21 spectral channels combined, Chiavassa et al. 2010), L and M (31 spectral channels from Fig. 4 combined), and N band (17 spectral channels from Fig. 5 combined). Bottom row, left panel: colour composite images for the H − K (pink scale) and L − M (blue scale) bands. Bottom row, right panel: all the bands, including N (green scale), are combined. The photospheric structures (H to M bands) are located in the centre of the N band maps.