Work-around GitHub issue #4

"In Emacs v24, for Mac and Windows, this Monokai theme is showing a green
background instead of the proper dark gray background."

This is a temporary work-around until I sort out proper 256-color
terminal support as requested in GitHub issue #3.

Reference: https://github.com/lvillani/el-monokai-theme/issues/4
Thanks to: Uwe Dauernheim <uwe@dauernheim.net>