One of the great joys of writing is being able to play God with your characters. They are your creation. So what are you going to do with them? Are the first impressions they have of other characters in your story going to be right or wrong? If the latter, how badly wrong? Do they stick with their prejudices or are they "man" enough to admit they did get it wrong?
What are the first impressions your characters give to your readers and are you sure these are what you want them to be?
Fairytales are often direct with first impressions. It is usually easy to tell who the hero/heroine will be, likewise the villain. Their directness is part of their appeal (certainly for me as a child and I still like this directness now. I also like the direct matter of fact approach about villains always getting their comeuppance).