CMDs of CNS5 objects in infrared. Top: CMD of the 2MASS sample. The blue points represent 2MASS sources cross-matched with Gaia EDR3, while the orange ones are not present in Gaia. Six extreme outliers are out of this frame. Bottom: similarly, a CMD of the WISE sample, with the blue points representing WISE sources cross-matched with Gaia EDR3, while the orange ones are not present in Gaia. Two extreme outliers are out of this frame.