I like high contrast. I think the bottom blue may be the same value as the verticle brown. I think the top two/left have the most value contrast to the two verticle. I don't know the pattern you mentioned, so I'm going at this like a mystery quilt. It's have do make decisions without the pattern. I think high contrast is more masculine for your boy.
A gentle and soothing combination might be the ferns and bottom blue.
I also had a SAB and it took a long time to recover.