I get very pale print from Scribus. Can you give me any advice, how shall I adjust the color management in the preferences? Is there any optimal constellation? I saw that Littlecms would help, I downloaded it but I cannot install it. Can you help me with this too?

Go to Document Settings - Color Management.
Set the values as you want:


Select the perfect Output color profile at 'Printer'.
For coated hard cover books Euroscale Coated v2 or similar
For home print to cheap paper Euroscale Uncoated v2 or similar
Click OK.
On creating PDF or sending to printer you have to select 'Printer' at 'Color' tab in printing dialog box so that all colors will be converted to CMYK.
Don't forget to switch on color management before printing.
Anyway, don't forget Inkscape works in RGB. Scribus has to convert all RGB colors to printer color space. So you'd better care about color settings.

What operating System do you use? In Linux Lcms is installed. You'd better download the package containing the useful color profile definition files from Adobe.

Thank you brtkr. I use Windows Vista now. Your help is valuable.

I'm happy. Do you have ICC color profiles?
If you recently installed any Adobe product (ie. Photoshop or Indesign) all the ICC (and ICM) files are installed in your Color folder in Windows (as I remember).
I'm not sure that Scribus will find these files so you have to set the correct path to ICC folder in Preferences, too (you can set whan no document is opened)
General - Path - ICC profiles

What about Lcms?
I think Scribus cannot installed without it in Linux.
Windows has own color management, so you don't need install lcms I do think and hope.

Vista has a new color management system. I don't know that Scribus can work with it.
http://www.colorwiki.com/wiki/Vista's_New_Color_Management_System_-_WCS

Anyway try to download and install the following installer:
http://sourceforge.net/projects/gnuwin32/files/sed/4.2-1/sed-4.2-1-setup.exe/download