Relationship between effective temperature (log T_eff) and intrinsic infrared color (J − K)₀ for the binary star sample. The dashed line represents the theoretical main-sequence (Luminosity Class V) track, while the dotted line indicates the giant (Luminosity Class III) track, both adapted from A. T. Tokunaga (2000). Blue circles and orange triangles denote detached and contact systems, respectively, with internal magenta squares identifying components with known stellar spot activity. The intrinsic physical properties were recovered by correcting observed infrared indices for interstellar reddening; specifically, Gaia-derived E(BP − RP) values were converted to a color excess E(J − K) and subtracted from the observed colors to yield the dereddened (J − K)₀ indices.