Abstract: The composition comprises: (a) a compound of formula (I), (b) a polymeric matrix comprising a crosslinked polymer, the matrix having a viscosity value comprised from 1×10?3 to 1×1012 Pa·s, (c) a redox pair, and (d) a solvent, the compound of formula (I) and the redox pair being embedded in the polymeric matrix; and wherein: R1 and R2 are selected from: a (C1-C20)alkyl; (C1-C20)alkyl substituted; a 2 to 20-member heteroalkyl; a 2 to 20-member heteroalkyl substituted; (C2-C20)alkenyl; (C2-C20)alkenyl substituted; (C2-C20)alkynyl; (C2-C20)alkynyl substituted; and a known ring system; R3 to R10 are selected from hydrogen; (C1-C20)alkyl; (C1-C20)alkyl substituted; and nitro; and X is a monocharged anion. The present invention also relates to processes for its preparation and to devices comprising it. The multichromic composition shows a short switching time and low transmission in the most visible range, which makes it effective in blocking the whole visible radiation in smart windows.