- Support for the CIE L*a*b* and CIE HLC color models, which are also available in the color editor;
- Support for SwatchBooker's SBZ file format, which means, among others, that all color palettes from the Open Colour Systems Collection can be used inside Scribus with their original colour model (CIE L*a*b*) intact. Moreover, Scribus 1.5.1 can now use Adobe Color Book files (ACO), as well as Adobe Swatch Exchange files (ASE).
- The import filter for XPress Tags is finally working as expected (some minor glitches notwithstanding) and has been tested with XTG files from XPress 3 to 2015;
- Two oft-requested text import filters have finally made their way into Scribus, namely RTF and DOCX;
- Scribus 1.5.1 enables applying a background color for selected text and also offers this option for character and paragraph styles;
- The ODT importer has been rewritten from scratch and now not only supports more ODT features, but is also much more tolerant with ODT files written by programs other than LibreOffice or OpenOffice.
- An experimental version of an import filter for FreeHand files has been added;
- PDF import has been massively improved;
- The font embedding code, as well as the related user interface, has been completely rewritten;
- The Resource Manager for online resources provides a new option to show the licence for the respective resource before downloading.
- As of version 1.5.1, Scribus includes two new color palettes, namely CIE LAB and CIE HLC. They are the first palettes in Scribus to use CIE L*a*b* color values.