Hardness–intensity (left) and colour–colour (right) diagrams based on MAXI data. Blue circles represent all MAXI daily measurements for each source in the shown energy range and between MJD 57000 and 58000 (as representative from the MAXI lifetime). The cyan square point is the MAXI daily measurement at the time when the ALMA observation for each source was performed (see Table 1). For Cyg X-1 there were no MAXI data available on the day of the first observation, and consequently only the second observation is shown.