Hi Morris,
First, check that your scanner is calibrated properly. A poorly adjusted scanner and screen can skew results considerably. Find an image with a white object and adjust scanner controls accordingly, and use a testcard to check your screen. Secondly, if the images with the very blue and slightly yellow casts are on the same film, it's probably not the chemicals; the cast would be consistent over the whole film unless you did something really weird. If that doesn't help, check your workflow and make corrections.
If you can post a scan, somebody might be able to diagnose the problem more accurately. Unlike B+W, colour developing needs accurate temperature and time control - it takes a little practice to get things right. And any cross-contamination of the dev with bleach-fix will cause problems (but not vice-versa).
Have fun,
kevs