all (the) one
1. The same as other options. Voting for a democrat or a republican for president is all one in my opinion; they're both going to lead the country the same way.
2. Making no difference or of no consequence to someone. To be honest, I don't care if we buy the blue or the red sofa; it's all the one to me.
be all (the) one (to someone)
To make no difference (to someone) one way or another; to be unimportant (to someone) what happens. I'd actually prefer to continue working on a freelance basis, if it's all one to you. It's only a game, after all, so it's all the one whether we win or lose.