I don't think it's strange at all. I think of leather (in brown/black) in general as a "neutral."

In general, if you're going to mix shape and texture, you can still pull the room together with color.

Do you have color options with the leather chair?

There are a few color choices. The room has a brown/beige in the oriental rug, we have some black furniture (wall unit), a red sectional, and a tan/red/white/ stiped chair and ottoman. So I guess the easiest color would be just to stick with brown then....although I've seen that redish brown color too and that seems nice althougha bit risky for us at least

I think brown leather would be fine. Just like sueb20 said, it would be a neutral. Besides you have brown everywhere else. It would be more to tie everything together.

I love mixing furniture in the same room. It sounds awful, wish I had some pictures to share from my last home. Our family room had a leather sofa, a large upolsterd chair and two wicker chairs as accent chairs. the colors worked and the pillows etc pulled it all together. YES it can be done!

Here's what I have in my living room: dark brown leather sofa; lime green (yes, I said Lime Green) leather chair; maroon velvet chair; and a chair that has a swirly print that includes the lime green and the maroon. If that isn't a weird mix, I don't know what is... but it works! (For me, anyway.)