Wedding attire for bf

In 2 weeks, one of my college friends is getting married. I have my dress and shoes already. My dress is magenta and my shoes are nude. (Pic of dress below)

My boyfriend was invited too. However, we’ve been looking for a magenta button up for him and cannot find one anywhere. He also keeps saying no to wearing a tie... but, I think it’ll be easier for him to wear all black or black pants white top and possibly a magenta tie.

Does anyone have any suggestions on what he could wear/should wear to a spring wedding?