Well, in terms of the science of artificial selection, mutations will be useful in achieving your goal as a genetic mutation that happens often in insects, particularly fruit flies, is a change of color. A strategy that could be used would be a Punnet square to simulate the possible crosses between the insects and which is most likely to bring out the recessive gene (the desired color). Finally, the breeding of dogs can be explained by humans breeding tall dogs with other tall dogs to ensure that the outcome would most likely be another recessive gene (tallness) and a similar set of events would explain the Pomeranian (short dogs being breed with other short dogs)
