[name_m]Hi[/name_m]!
Husband and I are TTC number 3 and we have two great kiddos already. I may already be preggo but I haven’t had a positive test yet. So hubby and I are trying to figure out what names we like and so far we’ve yet to agree. So I’m here asking all you lovely folks to suggest some middle names 
Our son is named [name_m]Colin[/name_m] [name_m]Nathaniel[/name_m].
THE NAMES–
[name_m]Callum[/name_m]
[name_m]Declan[/name_m]
[name_u]Elias[/name_u]
[name_u]Elliott[/name_u]
[name_m]Ethan[/name_m]
[name_u]Finn[/name_u]
[name_m]Harrison[/name_m]
[name_m]Isaac[/name_m]
[name_m]Killian[/name_m]
[name_m]Liam[/name_m]
[name_u]Logan[/name_u]
[name_u]Seth[/name_u]
[name_m]Silas[/name_m]
What a list! I love it so much! Here’s a few suggestions taken from your list:
[name_m]Killian[/name_m] [name_u]Logan[/name_u] ([name_m]FAVORITE[/name_m])
[name_m]Harrison[/name_m] [name_m]Silas[/name_m]
[name_u]Elliot[/name_u] [name_u]Finn[/name_u] or [name_u]Finn[/name_u] [name_u]Elliot[/name_u]
[name_m]Callum[/name_m] [name_u]Elias[/name_u]
[name_m]Liam[/name_m] [name_m]Declan[/name_m] or [name_m]Liam[/name_m] [name_m]Killian[/name_m]
[name_u]Logan[/name_u] [name_u]Elias[/name_u]
[name_f]Hope[/name_f] this helps! 
I think [name_m]Killian[/name_m] and [name_m]Callum[/name_m] are a little too close to [name_m]Colin[/name_m] for my liking, so I would stick either of those in the middle.
The ones from the list I think fit best with [name_m]Colin[/name_m] are [name_u]Elliott[/name_u], [name_u]Elias[/name_u], [name_m]Silas[/name_m], [name_m]Liam[/name_m], [name_m]Declan[/name_m] and [name_m]Isaac[/name_m].
Middle suggestions for those:
[name_u]Elliott[/name_u] [name_m]Henry[/name_m]
[name_u]Elliott[/name_u] [name_m]Jasper[/name_m]
[name_u]Elliott[/name_u] [name_m]Hugo[/name_m]
[name_u]Elliott[/name_u] [name_m]Liam[/name_m]
[name_u]Elliott[/name_u] [name_u]Logan[/name_u]
[name_u]Elliott[/name_u] [name_m]Isaac[/name_m]
[name_u]Elias[/name_u] [name_m]Callum[/name_m]
[name_u]Elias[/name_u] [name_u]Logan[/name_u]
[name_u]Elias[/name_u] [name_m]Declan[/name_m]
[name_u]Elias[/name_u] [name_m]Henry[/name_m]
[name_u]Elias[/name_u] [name_m]Leo/name_m
[name_u]Elias[/name_u] [name_u]Emmett[/name_u]
[name_u]Elias[/name_u] [name_m]Edward[/name_m]
[name_m]Silas[/name_m] [name_m]Killian[/name_m]
[name_m]Silas[/name_m] [name_u]Finn[/name_u]
[name_m]Silas[/name_m] [name_m]Julian[/name_m]
[name_m]Silas[/name_m] [name_m]Frederick[/name_m]
[name_m]Silas[/name_m] [name_m]Hugh[/name_m]
[name_m]Silas[/name_m] [name_u]Jude[/name_u]
[name_m]Silas[/name_m] [name_m]William[/name_m]
[name_m]Silas[/name_m] [name_u]Elliott[/name_u]
[name_m]Liam[/name_m] [name_u]Elliott[/name_u]
[name_m]Liam[/name_m] [name_m]Edward[/name_m]
[name_m]Liam[/name_m] [name_m]Sebastian[/name_m]
[name_m]Liam[/name_m] [name_m]Oliver[/name_m]
[name_m]Liam[/name_m] [name_m]Nicholas[/name_m]
[name_m]Liam[/name_m] [name_u]Sullivan[/name_u]
[name_m]Declan[/name_m] [name_m]Isaac[/name_m]
[name_m]Declan[/name_m] [name_u]Elias[/name_u]
[name_m]Declan[/name_m] [name_u]Emmett[/name_u]
[name_m]Declan[/name_m] [name_m]Hugh[/name_m]
[name_m]Declan[/name_m] [name_m]Oliver[/name_m]
[name_m]Declan[/name_m] [name_u]Seth[/name_u]
[name_m]Isaac[/name_m] [name_m]Edward[/name_m]
[name_m]Isaac[/name_m] [name_m]Oliver[/name_m]
[name_m]Isaac[/name_m] [name_m]Sebastian[/name_m]
[name_m]Isaac[/name_m] [name_m]Nicholas[/name_m]
[name_m]Isaac[/name_m] [name_m]William[/name_m]
[name_m]Isaac[/name_m] [name_m]Julian[/name_m]