Wanna take a look at the colors in our historic postcards?
Thanks to Laura Wrubel from the George Washington University Libraries in Washington DC, now you can!

We took [her code](https://nbviewer.jupyter.org/github/LibraryOfCongress/data-exploration/blob/master/Dominant%20colors.ipynb),
adapted it to use [our postcards](https://labs.onb.ac.at/en/dataset/akon/) as a data source,
tweaked the computation algorithm a little,
and the results can be seen on [https://labs.onb.ac.at/en/topic/akon-swatches/](https://labs.onb.ac.at/en/topic/akon-swatches/).

Here, you find the two Jupyter Notebooks we used to tweak the algorithm,
a Python script to actually compute the color data (this takes us about 4 hours),
and a `requirements.txt` for your own Python virtual environment.