Nick,
No issues with yellowing. I've used a few different brands of cures.
To get started, I'd recommend buying a tube of Loon Knot Sense and a UV light.
The Knot Sense will cure with a bit of tackiness. Set it outside in the sun for a final cure or put a coat of Sally Hanson's Hard as Nails over the top.

I've been using a new to me brand with good results. The light I bought with it is super powerful. If you hold it on the cure for to long rather then wanding it ober it the cure will actually start smoking.
The cure time is incredibly fast with no tackiness. After using the UV cure I don't ever see myself going back to epoxy.
SF