All of my RTV molds did this over time. Funny thing is.........you said it did it with just a few pours? Never heard of that one. It usually takes hundreds of pours to make them turn yellow. Also King Bait is VERY lucky. I have never met an RTV mold that doesn't turn yellow.
That is simply from the oils in the plastisol. Nothing to worry about. Won't effect the bait and/or colors at all. The only thing you have to worry about is over time the RTV molds will produce a dull looking bait. You can help this by: 1) baking your molds in the oven at 350 degree (NO MORE THAN 10 MINUTES!) or 2) using worm oil in your cavities before pouring. Just make sure you do a clean sweep with your finger or Q-tip so the oil doesn't puddle.
Carry On!
