Blanket for rainbow baby?

Hey ladies! My SIL is expecting her rainbow baby (a boy) in May and i wanted to crochet a blanket and hat set for him, but instead of using the usual blues and greens for a boy, was thinking of making her a rainbow blanket or a mostly white with rainbow stripes or something. She likes colors and i think it would make the blanket even more special for this little guy, especially considering she's struggled to conceive for quite some time now.

Any ideas or inspiration you could throw at me?!

I was really leaning towards a chevron style to make the rainbow colors sort of pop out and not look so 'basic' but I'm not sure. Lol