I don't think "Be Creative" have to force you to do satanic shit.
My guess is that this is showing how easily kid-programs can manipulate kids. By not having green in the colorpalette means, it isn't a creative color.
It's a simple message: "Get creative", with submessages as "Green is not a creative color".
Of course this one is painted black on white so it's so obvious what's happening and the results are of course overreacted, but they're just saying that it's possible.