Blackmagic Intensity Pro colour space issue?

Hi!
I have both a BMD Intensity Pro and a Pro 4K. I’m wanting to output analog composite SD video via the breakout cable and S-video adapter, through the Video Device Out TOP.
Both BMD cards give me an image with a yellow cast: is it an RGB-YUV issue?

I’m using the latest download of TD and BMD drivers.

Any help well appreciated!!
Philippe