The pair star in Harry Macqueen's drama movie as Sam and Tusker, a couple who travel across England to meet with family and friends as Tusker is suffering from dementia, and Stanley enjoyed sharing screen time with Colin.
He said: "I love him. We've been friends for over 20 years. He's an incredibly good person and a great friend. He's a great father, and he's just one of the best actors ever.
"And we have the best time together. We don't seem to get bored of each other, which doesn't really make any sense because we're not very interesting."
Stanley, 60, plays Tusker in the movie with Colin starring as Sam but the pair were originally meant to play the opposite roles.
Tucci told the website Collider: "I think that we did it the way we were supposed to do it. But yeah, Harry offered me the role of Sam and that was the way we went into it. Colin was gonna play Tusker and then I kept reading it and thinking, 'Something's wrong. I wonder if we (switch).'
"And then Colin comes to me one day, he goes, 'We should switch roles.' And I said, 'Yeah, I've been thinking the same thing.'"
'The Devil Wears Prada' star continued: "So we went to Harry and, poor Harry. It was just like, 'Oh god, why did I get stuck with these two?' And then he said, 'Alright, well, let's read it. Let's pick some scenes and we'll read them one way, we'll read them the other way.'
"And we did and it was pretty evident that that was the way it was supposed to be."