A keen Fremantle Dockers fan in Western Australia's north west has painted his house in the team colours.

Dayne Corps, 28, from the mining town of Karratha says the new paint job took place as a bit of a joke on his birthday.

But, he says, he has been a keen supporter of the Dockers since they first joined the AFL 19 years ago.

"Ever since they started," he said.

"It was the whole underdog theme actually, liking something that no-one else liked and the crowd just basically growing from there and I think everyone loves them now, they're exciting."

Mr Corps says supporting Fremantle has not always been fun.

"It's been pretty painful at times but it's great to seem them now," he said.

"They've played some great footy. I love watching them."

Despite going into tomorrow afternoon's game as underdogs, Mr Corps says he thinks Fremantle can go the distance and is tipping them to win by nine points.

"If they keep playing like they did on Saturday night as everyone saw, I think a really, really good chance," he said.

"I think they're a young team. I just hope they go for it and leave nothing left in the tank."

Mr Corps says there will be some key match ups on the day.

"Definitely Ryan Crowley on Sam Mitchell will be a big one," he said.

"Chris Mayne if he kicks some big goals up forward, Nat Fyfe if he can take a couple of marks and Michael Johnson and McPharlin off the backline there; if they can keep their forward line down, especially Buddy Franklin to one or two goals, they've got a really good chance."

So what is this die-hard Dockers fan doing on grand final day?

"Actually it's my mates bucks party day so we're doing a tour de fridge," he said.

"We have to do ten houses, two beers at every stop before 12.30, so I don't know if I'll get to see a lot of the grand final but it's gonna be a good day either way."