I would NOT deviate from the published times: I use Tetenal in the JOBO, and Color Developer for 3' 15" at 38C seems to be standard. Bleach-Fix can vary from 4' 00" to 8' 00". I'd stay with the manufacturer's recommendations.

From memory... Photocolor Color Developer was a mixture of three solutions; "A", "B" and "C". "B" was the problem: originally, it is "light straw" in color - it will rapidly darken, and when there is an appreciable color change it is *SHOT*.

Strange ... I've had that happen to me ... I purchased a Photocolor C41 "Kit" and when I got it home found that it had been opened, the chemicals half used - and solution "B" was BLACK - and "chunky". I brought it back ... more or less screaming. Their attitude was ... "Oh yeah, That happens. Here is a new kit."
No emotion whatever. That cost me a 70 mile round trip into the heart of Boston, and four days of delay ... and all they could say was, "Oh yeah .. that happens..."

Shelf life is a problem with color chemistry. The only dry chemicals I can find on this side of the pond are Tetenal's C41 "Press Kit" - at about twice the cost of their regular wet chemicals. All in all, this may be the most cost effective way to go.