A solution to the <a href="https://en.wikipedia.org/wiki/knight%27s_tour" class="extiw" title="w:knight's tour">knight's tour</a> attributed to Euler.  Start in upper left corner.  Color changes from peach to periwinkle as tour progresses.
<a href="//commons.wikimedia.org/wiki/User:Nonenmac" title="User:Nonenmac">R. A. Nonenmacher</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>