MAXI/GSC hardness-intensity diagram of GRS 1915+105 from daily monitoring observations since August 2009. The blue data points (both dark triangles and light blue squares) indicate the low-luminosity state since August 2018 with increased spectral hardness. The light blue squares correspond to the obscured decay phase with even lower flux densities and harder spectra with occasional, strong X-ray flares (red diamonds) and highly variable radio emission, in addition to a softer state in August–September 2020 with the flux densities back to the level of the low-luminosity state (yellow dots). The numbered green boxes correspond to the ALMA epochs that took place during the linear and rebrightening decay phases of the outburst decay.