Schilderij No.2 "mit Blau, Gelb, Schwarz und verschiedenen hellgrauen und weissen Tönen", 1926
Yellow with blue, black and various shades of light gray and white.
Loaned by Sophie Küppers to the Hannover Provinzialmuseum, confiscated by the Nazi authorities in 1937 and stored in Niederschönhausen as #7034.
The only image of B174 with another extant Mondrian painting (fig. 1) is from a 1926 exhibition in Amsterdam that also showed the diamond painting, B173 (fig. 2).
The area of blue is not really large enough to provide any clear guidance on the reconstruction, though the painting's title is hellpful in specifying yellow, blus and black.
Fig. 3 from Entartete Kunst, Berlin gives a better view of the painting but does not allow colour comparisons (this photograph might have been cropped from a wider view, but an example has not been found.
The Catalogue describes the painting's signature as "lower right on blue(?)" which is hardly decisive but must have some reason behind it. That should make the top right yellow, and that makes sense as it is the largest area of colour and yellow is the first colour mentioned in the title.
So what about the black? I have no answer to that.
Fig. 4 shows the reconstruction without black.