I only have experience of blue roans, but they generally get darker as they age! (mine certainly did - when we first saw him we worried he wasn't going to be dark enough, and now he's very dark, although some of that puppy fluff has now gone and some silver is showing!).
If Leo is mainly orange now I suspect he'll stay that way. He's adorable, by the way - haven't been on here much recently, so have only just seen the photos. Congrats on your new addition!