Not a pro but wouldn't think the color difference would matter. If you find it does, you might consider a sealer for the deck that would darken it a bit.

Never heard of someone co-ordinating deck with interior - exterior - but not interior.

Since the sliding door is going to open fairly wide, I was thinking of how these two would look. I suppose it seems like I can get away with it, but would probably want to make sure I create a look that's pleasing. Going darker seems like an option with the sealer.

Be assured, whatever you do the color is not going to stay the same if the deck is

outside. Weather usually will change the color.

You ARE overthinking it.

They look fine together.

I happen to think decking is best when very close to interior flooring or at least in the same color family . If you planning on letting the IPE weather I think they will work well together