Got it, firmware 1.4.2_0044 received and installed correctly:
And finally, BLU is BLU, thank you Yeelight team, never got such kind of support from other companies, keep up a very good work this is your "winning card".
Maybe the photos don't show correctly the changes, but I can assure that the BLU is shown now in a perfect way.
This is BLU/PURPLE before firmware update:
And this finally the REAL BLU: