Today Sigma released a small firmware update for the DP Quattro series, including the DP0, Dp1, DP2 and DP3. The update concerns the software algorithm and improves white balance and colour reproduction accuracy. The colours of the JPG and RAW files are also enhanced when the latter is post-processed with the Sigma Photo Pro software.
To show the difference in colour between the new firmware and the previous firmware, Sigma published a dedicated page on their global site. Specifically, they demonstrate the improvement in the green of the leaves, blue of the sky and the skin tones.
Please note that after the new firmware is installed, the RAW files (X3F) will only be compatible with the Sigma Photo Pro version 6.3.2. Make sure to update your software as well by following this link.
The firmware updates for the different cameras can be downloaded from the following links. Make sure to follow the instructions to update the camera correctly: