Wedding colors/family colors

The family can wear whatever color they want. They aren’t photographed with the wedding party anyway.

They dont have to match or be assigned colors. Let them wear what they want.

I only asked my parents and my kids and their siblings to wear shades of a certain color for family pictures.

I think unless in wedding party family wears what they want.

You don't always pick what the family wears. But that being said my family and my fiance's family volunteered to let me pick their outfits, you can suggest a color but don't get dissapointed if they don't follow through.
I'd say a light coral color would look good with the red or even a dark wine or maroon color depending on your location and time of year.

I let my family wear colors close to the wedding colors but didn't let others

It is becoming s thing they do & I hate it! I say COMPLIMENTARY colour not matchy! If the Bridal parties in Red out family in dusty pink and rose gold. They stand out but not in red to match.

Typically parents and families pick out their own attire, but many will still want to be mindful of your party so as to avoid blending in like you mentioned. Since my mom and FMIL were there when we picked out the bridesmaids dress (steel blue) they knew what to avoid. Both moms are opting for navy blue which is neutral and not in my palette.