Dress etiquette morning wedding

Don't say anything. Let adults decide what to wear for a wedding.

I just need to convince family of that

Adults can dress themselves. Khakis are perfectly fine for a morning wedding.

Khakis are okay for a morning wedding, especially I believe since it extends to afternoon.

Other than black tie, dress codes are not to be on wedding invitations.

It's actually kind of funny that you are worried about etiquette when the men are wearing tuxedos to a morning wedding.

Putting semi formal won't help. Anyone who would wear khakis to a wedding won't care what your dress code is.

It is borderline tux/fancy suit

Do you have a link or a pic? It's either a tux or a suit.

What's wrong with khakis at a morning wedding?

Also, how is your wedding borderline tux/fancy suit? By default, morning weddings are generally more casual so I'm not really sure how you are getting this idea that everyone needs tuxes...

Joseph Abboud Black Peak Lapel

Thank you all so much for your comments and advice. I really appreciate them

That's a tuxedo.

I wouldn't say anything

OP, if your family is asking you specifically what to wear you can let them know semi formal and then let them decide for themselves. Never put requested attire on an invitation unless it's truly a black tie affair. I'm sure your family can spread it word of mouth to your relatives if they ask. Word of mouth is how things were done for weddings for decades and it still works.