It's possible, but not necessarily true. Every animal has two copies of DNA for every trait. For example, a dull parent may carry two copies that tell it to have dull colors, or one dominant copy for dull color and one recessive copy for bright color (which is covered by the dominant dull). In breeding, each parent passes on one of their copies to the offspring. Both parents can pass off the dull copy to produce dull offspring, or the offspring could get one of each and appear dull, or it could inherit two bright copies and appear bright. So by just looking at the parents' appearance, you can tell what the offspring MIGHT look like, but not what they WILL look like. You need to know their true genetic makeup to determine the probabilities.