khaki drakes are the prettiest, here is my khaki boy latte and my khaki mix boy blackberry (sadly blackberry passed away last year but both of them are/were amazing pets)
they will both get their full drake colors at 3-4 months old, at first they’ll look like females
yours is definitely a mallard, rouens are double the size and have two full eye stripes
mallard drake (the one with eye stripe)
khaki drake (dark brown one)
and the white is runner (i think drake)
do not worry about “too many males” if they all end up being boys, all drake flocks are great!