Yes, brown is dominant.
My husband has brown eyes and his dad has blue eyes. My husband's sperm carries both blue eyed and brown eyed genes. I have blue eyes.
My daughters have blue eyes, but their eggs can also carry the brown eyed gene because of their dad.
If they marry someone with blue eyes, their children can still have brown eyes because it takes both sets of genes to make blue eyes.
In my brother's case, we have both blue-eyed and brown-eyed ancestors. Our parents are both blue-eyed, but I know that at least one of my grandparents had brown eyes.
My brothers eyes are not as dark brown as my husband and my son. Maybe they would be considered hazel, but we always said he had brown eyes.
There was no infedelity either. My brother looks just like my dad accept for his eyes (and he looks like me), and he was definitely carried by my mom.
"My daughters have blue eyes, but their eggs can also carry the brown eyed gene because of their dad."
Nope. If they have truely blue eyes, they have two "blue" alles.
(Each sperm carries 1/2 of your husband's DNA. Just happens that the 1/2 they got was "blue")
The other possibility is that your daughters don't have "true" blue eyes, but rather hazel --- a mixture of blue/brown.