About Directmedia has provided 10,000 paintings from the 'York Project DVD "10.000 Meisterwerke der Malerei" (10,000 Masterpieces of Painting) and the associated metadata to...

An index of the paintings available on Wikimedia Commons.

Over 2 million freely usable media files to which anyone can contribute

A REST API to search the V&A's collection. Sadly restricted to academic and noncommercial use. Search for items by keyword, artist/maker, collection, year,...

"over 100,000 digital images free for use in education"

Various RDF datasets from the National Gallery. Some appear to be under an original-BSD-style licence, which I believe amounts to an attribution licence.

A screen-scraped RDF/SPARQL database of artworks in various UK government collections. See here for details of how the data was assembled:...

"The project team has compiled a comprehensive database of all Celtic art found in Britain to date. This includes excavated finds, and finds recently reported to the Portable...

"Permanently sited public art works funded by percent-for-art ordinance"

A database of over 70,000 objects in The PowerHouse Museum in Australia.

The Noun Project collects, organizes and adds to the highly recognizable symbols that form the world's visual language, so we may share them in a fun and meaningful way. More...

"NI 9 Use of public libraries NI 10 Visits to museums and galleries NI 11 Engagement in the arts"

A project of the University of York and the Tate to create linked data for a dataset of "The London Art World 1660-1735". Currently in progress, with the ODbL as forerunner for...

About From the website: This is an experimental service that makes the ICONCLASS Iconographic Classification system available as linked-data using the SKOS vocabulary. This...

"Hard commitments awarded to successful grant applicants. Dataset includes unique reference number, name of recipient, project name, amount awarded, date of award, region, local...

Data regarding artworks, artists, museums and other visual art subjects. Tab-delimited data dump available. Licence is CC-BY, although the attribution page says "Many Freebase...

User-generated tagged colour palettes. With a nice API.

Comma-Separated Value dataset of 10,000 colours and the labels applied to them by Amazon Mechanical Turk clickworkers. Archive contains the dataset and useful accompanying...

An article showing colour palettes taken from famous paintings, with more in the comments. This isn't really a package, but it's a good resource and a great illustration of...