All of my children look different. Our bio Dd does not feel less loved because of her adopted siblings. It has been difficult in many ways, though, since we adopted special needs children and this has been demanding for ALL of us.
My adopted kids are still relatively young, but I don't think that they feel isolated because they all have different skin/eye/hair color. It hasn't come up. We have 5 kids though, so maybe if we only had ONE adopted child they might feel differently. Not sure.
We've found that having a new sibling join the family (whether by birth or adoption) there is a transition time and a process that takes a bit of time and patience, regardless of any extraordinary factors. (Extraordinary factors might be having a new sibling be a toddler or older child, a child with special needs, etc.) Preparing the kids ahead of time helps. There are lots of children's picture books on having a new sibling join the family, and there are even books about adopting a new sibling.
We were also careful to talk with the kids already home after we had more children arrive. While it is normal to sometimes feel resentful of the time mom or dad spend with a new sibling we were careful to direct them in how to appropriately deal with these feelings (ie: come to mom or dad and talk with us) and to remember that mom and dad loved them just as much as ever before. We would go for walks with each of the other children, or have a special story time with just the two of us, etc. We also made sure to inlcude the older kids in helping with the younger kids.
This does not mean that all of our kids have always been happy and loving towards their siblings! LOL It is a work in progress.
Many of the fears we had prior to the arrival of each of our children have never actually come to be. We've not encountered any screaming racism, or cutting comments (to our faces, anyway!). We may sometime, but haven't so far. (We started adopting about 9 years ago.) The comments we do get are about the kinds of issues our kids have; namely, drug/alcohol exposure/addiction. While it isn't ok to talk about race, it seems to be perfectly permissible to speak about our kids special needs. Sometimes this is no big deal (people just want info and are curious in a kind way) other times it is a bit over the top (stereotyping, derogatory statements about our kids' futures, etc.).
Hope some of this helps.
