I am noticing a slight colour shift in FCP during an edge wipe transition. The rendered frames during the transition are noticeably greener -- especially obvious in green elements in the shot 9they become a slightly lighter/brighter shade of green). I see it in the Canvas, the broadcast monitor and the (external) scope.

The clips are uncompressed 8-bit 4:2:2 as is the sequence. Video processing is set to 8-bit YUV. Render control is set to "Same as Sequence Codec". Using FCP 6.0 on PowerMac G5 with Kona 2.

Any ideas?

I have tried using other transitions (edge wipe, cross-dissolve, non-additive dissolve, etc) and it happens on all of them. Very odd.

With your sequence open in the timeline, using different video processing settings might change something. You've got RGB, 8-bit YUV, 10-bit YUV and all YUV material in high-precision YUV. Also check the Kona capture settings, there might be something in the Codec that you're not taking into account. Is it the Kona 8-bit Codec or the one that came with Final Cut Studio. Also try transcoding a few clips to ProRes (HQ) the apply the transitions as normal. Also, also try changing the render setting to a different codec. I know my video capture card added a lot of codecs, so there could be a mismatch somewhere in the software. One setting could be using the Kona 8-bit and a snother setting cold be using the Final Cut Studio Codec.