no it actually doesnt, unless you greatly over heat it. ive gone through several drums this year and have had no issues what so ever with yellowing. with the ammount of stabilizer they use in the plastic you shouldnt have an issue. would really hate to see you miss inform someone just starting out.
I use Calhoun, tried most (except for CCM) and keep going back to Calhoun. is it for everyone? NO. is any plastic for everyone? NO. to tell someone they should use a particular brand as their first because it will work best for them (which really is a preferance kind of thing anyway) is some of the worst advice i have ever heard given out on here. I will be honest, if i tried M-F as my first plastic i wouldnt be pouring still, i find the odour while cooking it unbearable and caused me sevear migranes, i also found it to be VERY oily after molding it.
In short, if you are starting out, call everyone of the plastic suppliers and tell them you are just starting and trying to figure out which plastisol will best suit your needs, and if you can get a sample to try. you will have to pay shipping in most cases, but most should be willing to send you a sample, then you can form your own opinion instead of following some one elses.