Quadrat Bottrop – Josef Albers Museum & Museum Center

Bottrop Museum for Ur and local history but also for art.
In addition to interesting facts from Bottrop as the city developed and some old beams of farmhouses that had to give way to mining, you can also find exhibits from the Ice Age such as a mammoth skeleton and a woolly rhino. In the modern area, the "artist" Josef Albers has been commemorated not only by the name square of a world-famous child of the city.
Albers March 19, 1888 in Bottrop; † March 25, 1976 in New Haven, Connecticut)
For color studies, he painted squares in ever new color variations where the viewer even when looking closely, despite often the same color in the middle of the hue times brighter times darker and sometimes color shift works.
"The simultaneous contrast is not just a peculiar visual phenomenon-it's the heart of painting," Albers said.

bottrop.de/mq/index.php
And here's a page that generates random color variations:
tomatoco.de/valbers/formsucher.html

opening hoursTuesday to Saturday: 11am - 5pm
Sundays and public holidays: 10am - 5pm
Always closed on Mondays.Admission to the collections (Josef Albers,
Ur- and local history) is free!The entrance fee for the current temporary exhibition
is 6 euros / concessions 4 euros.For Bottroper citizens is the entry into the
Temporary exhibition free on Fridays.The museum is open on the 24th, 25th and 31st of December
and closed on January 1st.