Surface modulation signals in stars of NGC 2516 sorted by Gaia colour index. Stars with smaller colour indices are displayed at the top. Frequency (in d⁻¹) is plotted along the x-axis. The y-axis, representing amplitude, is omitted for brevity. Each panel displays the amplitude spectrum in grey, with the rotation frequency indicated by a vertical red line. The TIC number and corresponding Gaia colour index are noted in each panel.