Hi Nick
I’m not sure if this is related but I have the 310 and did the update a couple days ago and having done a days worth of printing after the update I noticed I was having an issue with the drying of the ink, when checking I noticed the optimiser was still showing as 88ml left, (normally change around 30) but I remembered it had been on 88 that morning as well so decided to check and found the cartridge empty. Replacing solved my issue, do you perhaps have a low ink thats still showing ok that might be out. I’ve always found the levels pretty accurate before hand so not sure why its playing up now.
Apart from that issue i’ve not had any other problems with colour.