Hi,
Thank you for your question. The licenses for SDSS and DSS images are different because there are different contributing organizations to each. However, both are free to use for non-profits for educational purposes, without further restriction. This includes Wikipedia. There is no copyright STScI holds that would prevent using the DSS images on Wikipedia, even though it may not be specifically named in the DSS license.
Referring to https://archive.stsci.edu/publishing/data-use#section-95dab389-f4b4-4a52-8985-dcbfb908d8f2 it appears that use of the color DSS images can be investigated further by contacting archive@stsci.edu
Sincerely,
The Office of Public Outreach
If you need to contact us about this request, please reply to this message
Thank you