Are they litter mates and are they identical?

Dave is a little bigger than Chet and has a rounder face, so I can tell them apart up close. The collars help me identify them from a distance. Their personalities and voices are also pretty distinctive.

It’s wonderful that they get along so well.

Living with me, he was 15.5lbs. Pretty big boy. He just turned 13, I'm getting ready to call his original mom today and see how he's doing. He has two rambunctious dogs to deal with so he isn't a lazy cat. He's still the ruler of the homestead, house and yard.

Love yours, they look like happy cats.

necessary activity is, perforce, on hold. My kitty just woke up because the wind (which he hates) stopped, so he could leave Mom's lap.

Thank goodness he is not quite as large as Chet and Dave!

Do the collar colors reflect their personalities?

I can completely relate to your quandary, and no I don't move either.

but orange and blue are the colors of my alma mater, Macalester College in St. Paul. https://intercollegiate-registry.org/macalester-college/ So we're good.

Love the "Chet and Dave" cultural reference, though they were mostly before even my time.

I've concluded that Chet thinks he owns my lap, so whenever Dave parks himself there first, Chet arrives to pile on. If Dave leaves he stays, emphasizing his ownership. But I can get them to leave by using my phone (can't get to the laptop with their fat asses on me) to play a video where cats are meowing. That gets them all excited and they get down to look for the other cats, and then I can get my femoral arteries working again.