More a question than an answer, might I suggest that chemical ageing seems to be especially critical with color processing. After a month, whether chemically exhausted according to the manufacturer's specs or not, I have observed that color developer and blix become suddenly less effective. If, like me, you process only a few color rolls each month, you may want to accumulate a good-sized lot of exposed color film in your refrigerator, then mix up a fresh batch of color chemistry and process it all at once - observing the manufacturer's specs at least nominally.