Professional Darts Corporation star Peter Wright channeled his inner Grinch for his opening round of the World Championship on Tuesday ... by dying his hair bright green and throwing on a 'fit inspired by the iconic Dr. Seuss character!!

The defending champ made one hell of an entrance at Alexandra Palace in London ... doing some wild dance moves while Pitbull's "Don't Stop The Party" blared over the speakers.

Watch the video. It's super entertaining!!!!

But, the green grandiose entrance didn't affect the 50-year-old's game one bit -- beating Steve West 3-1 to advance to the next round.

Wright spoke about his decision to go full Grinch after his win ... saying, "It's all about trying to make people smile, because we've had a horrible year, people's had a horrible year, lost loved ones. People lost jobs and stuff like that."

He added ... "I just wanted to cheer everyone up. I think I've done that."

BTW -- Wright is known for his eye-popping looks ... from wild multi-colored mohawks to outrageous outfits.

When asked about his critics calling him a "clown," Wright says he simply doesn't pay it any mind.

"I don't care because it's me just trying to make people happy. If I lose, I lose, if I don't, I don't."

It's a pretty wild statement from Wright ... considering the tourney has a $3.37 million prize fund ... so there's money to be made!!!