The colour coding is ok, but then one (anyone, everyone, not the OP) has a brain-fart and chooses the wrong colour. I go for numbers on everything 1, 2, 3 etc. and then set the containers out in the right order and use them according to the usual numerical order.

Timing is taken care of by an Android app, which also beeps for agitation, and a backup kitchen-timer for the developer time. Fixer is tested for clearing-time before every run, then timed appropriately.

The critical point then comes with placing the correct chemical in each numbered container, but at least that can be done in a leisurely way, with extra time to check! However, three stages for black-and-white film should be simple enough almost every time (and I have now jinxed myself...).