Assuming that blue eyes and blond hair are recessive traits, there is a 25% (or 1 in 4) chance for each trait that any pair of parents would produce a blue eyed, blond haired child even if they both have dark hair and eyes. This is because every parent has 2 sets of genes, and for the most part only the dominant trait is expressed. When the parents mate and make a child, the child gets one set of genes from each parent. If each parent carries the recessive (not expressed) trait for blond hair and blue eyes, then the child can indeed have light hair and eyes even though the parents do not. Since you mention a sort of genetic family history that includes these traits at some point on each side, I would say it is possible but it also depends on the dominance of the traits for hair and eye color, of which I am not certain.
Hope that answers your question (with a little genetics on the side...)