What is going on on pageload?

http://www.manufacture-royale.ch/wp/

The header starts out with the correct styling (white/bold), then switches to black/normal spontaneously.

If I switch to a non-transparent header, the problem doesn\'t occur.

Note : color scheme settings.

No black anywhere.

http://i.imgur.com/4c1TOcn.png

EDIT : OK, got it. Transparent header color changes depending on the \"text color\" setting of the row below.