High-angular resolution observations were acquired for a sample of F-G and K nearby orbital binaries, making use of the ADONIS instrument mounted at the 3.6m ESO telescope from La Silla observatory. The aim is to derive broad-band near-infrared colours for the individual components of those binaries which do not fit well the mean mass-luminosity relation, but which have accurate parallaxes (from the Hipparcos satellite) and high-quality orbits, thanks to many previous efforts. Such colour determinations allow component temperatures and photometric mass ratios to be derived.
