[scribus] pdf/x-3 and color bars

[henry atting]

Hi,

I use scribus 1.3.4 
As far as I see it is mandatory to activate the checkbox for color bars
to export to pdf/x-3. Because if I do not so I get a pdf with RGB
colours instead of CMYK.

Is it possible to create a pdf/x-3 (with CMYK colours) without the
colour bars at the head of the page?

Cheers 
henry