Actually, I don't think you need to change the processing time to account for film sensitivity like in B&W!
Color films are designed to be processed for a standardized time in the same soup.
So once you figure out how long to process, no matter the sensitivity, the times will work.
You could do a test. Get a cheap roll of color film (1$ film should be good enough).
Expose an average contrast scene, same picture on all 24 exposures... that shouldn't take too long.
Then, do a clip test.
In the darkroom, pull a short length of film (6 inches), cut and process. Do the same with different processing times until you have processed all the film. Then choose the one you like best and process for that time/temperature.
If you have a film leader extractor, it's the time to use it! If you don't, just make sure the film doesn't get exposed by accident. Using an empty black photo paper bag is the best way to go. Kodak film cans with the gray plastic top might not be the best...