I have observed your requirements and it seems you are probably interested in extracting the font color from this portion of text. I have tried accessing the color values and it seems to be an issue with Aspose.Slides while accessing the color value. An issue with ID SLIDESJAVA-36430 has been created in our issue tracking system to further investigate and resolve the issue. This thread has been linked with the issue so that you may be automatically notified once the issue will be fixed.
We are sorry for your inconvenience,