Using Smooth-On 325, and MK GID resin dye. Doing a resin fill, its half clear and half white..
I'm no expert resin caster, but this is the first time I've seen this happen..
Any ideas?

While the picture makes it hard to tell the issue without an explanation, I would wager that it's separated or not curing/sticky
The bit towards the top of the figure where it gets "stringy" makes me think it's not curing properly.
That could be from one of two main things, one being something in the figure is not compatible with the resin and made it not cure, or the one I had trouble with early on, which is not shaking the resin enough and/or cold/hot resin.

Before you pour, make sure the resin is stored at the temperature shown on the container, it's not a suggestion and can cause lack of curing or very slow cure, the resin (both parts a and b) need to be shaken vigorously and given time (20-45 minutes roughly) to allow the bubbles to rise and pop so they are not in your mixture.

Just pointing out things that I had trouble with when I first started casting and using resin. Hope that helps.

Thanks oOMoSOo!
Yeah, now that I'm thinking about it, I'm afraid I may have over heated the resin.. I store it in my garage, along with my other resin/painting stuff and it got pretty hot a couple weeks ago. I'm pretty careful about the rest of the process, but the temperature is a definite possibility.
I'm going to do a test casting to see if I have the same problem before I go buy replacement resin.