(r – J0660) versus (r – i) colour–colour plots used to select objects with Hα excess. These plots display data for all stars from the S-PLUS DR4 MS, representing the PStotal photometry in these colours. The data are divided into four magnitude bins: (a) 13 < r ≤ 16, (b) 16 < r ≤ 17.5, (c) 17.5 < r ≤ 18.5, and (d) 18.5 < r ≤ 19.5. Objects with Hα excess are expected to be located towards the top of these diagrams. The lighter green and yellow points connected by lines represent the tracks for main-sequence and giant stars, respectively. These tracks are derived from the synthetic spectra library of Pickles (1998). The background colour gradient represents the density of objects: red indicates the highest concentration of points, followed by green, blue, and purple, which represent progressively lower concentrations.