Colour–colour diagram shows the distribution of Hα-feature sources in the (r – J0660) versus (r – i) colour–colour space. The data is divided into two populations: GDS and MS representing distinct galactic components. The GDS population, depicted by the filled circles (in green), corresponds to Hα excess sources associated with disk structures. In contrast, the MS population, represented by the squares (in orange), includes Hα excess sources primarily located in the direction of the Galactic halo and extragalactic sources.