Color shift on exporting from FCP
 

I have a video with some PNG-based titles that have a deep navy blue on them. They import into FCP and make slugs that seem to show the colors correctly within FCP, but upon export to Quicktime movie, the navy blue becomes a little purplish when viewed within Quicktime on the very same machine.

I am using H.264 as the codec in the export.

What am I overlooking?

Tony Lovell