This site is a demonstrator for the new Europeana API colour palette search methods. Information about these can be found on Europeana Labs. You can also now explore the available media search facets via the Europeana Collections site.
Beyond the powerful colour searching, the items retrieved here are filtered through these API methods to ensure that they are: all images; all licensed for re-use, either openly or with some restrictions (e.g. non-commercial or no-derivatives); all have directly accessible image files from the providing institutions measuring at least 0.5 megapixels.
The demo is entirely client-side and based on jQuery. Each page load makes a single API call to the Europeana API and from that retrieves information about individual items, including thumbnails, titles, and links, plus facets information for the results set to build the colour palette and navigation.
The code is openly licensed so please feel free to copy, modify, distribute as you please. It will be shared on Github shortly!