When may an offspring's trait be mistaken for a blend of traits of parents?

An offspring's trait may be mistaken for a blend of traits of its parents in cases of incomplete dominance, where neither parent's trait fully dominates, resulting in a phenotype that appears as an intermediate blend. Additionally, some traits can show co-dominance, where both parental traits are expressed simultaneously, leading to a mixed appearance. Environmental factors may also influence the expression of traits, further obscuring the genetic contributions from each parent.