I thought it was meant to be ironic, the white and magenta text on black so repelled my eye. But no, some (not all) of the other pages on the site are like that.
See author photo: https://github.com/tlevine
Side observation: He created two repositories with hundreds of fake commits so his Github activity chart would spell out "tom."
GitHub activity vandalism has been around for a while. e.g. https://github.com/gelstudios/gitfiti