Hardness ratio vs. X-ray count rate for Swift XRT data of Mrk 335 since 2007 (black). Three regimes are apparent: a softer-when-fainter trend at lowest count rate, a softer-when-brigther pattern at intermediate count rate, and a near-constant HR at highest count rate. Upper panel: full count-rate range. Green circles represent the 2020 outbursts. Lower panel: count-rate range up to 0.5 cts s⁻¹. The red lines represent the fits to the three regimes (Sect. 3.3), and the blue squares mark the median in each bin.