Variation in color, size and shape differ but always within its 'kind'.
Variations in color, size, and shape do not happen magically. It happens because of subtle differences in dna. So even though a species may look like other members of their species, they all have different genetic codes. And with every offspring each pair produces, the genetic code changes more.
Variation in color, shape, and size are exactly what evolution is and the difference between each "kind" of animal is basically variations in size shape and color, only the genetic code between the different "kinds" that is required to produce the different sizes, shapes, and colors has varied between these "kinds" of animals has varied to such a degree that reproduction can only be limited to "kinds" of animals that are very similar to their dna.
All animals are different from all other animals, we only look the same as our respective "kind" because our dna hasn't changed enough to cause too much variation in size, shape, and color.... yet. But with every offspring that is born, more variations are produced, natural selection chooses which variations, if any, will prove to be advantageous to life, and if that means one "kind" varies enough from its original "kind" to be classified as a different "kind" then so be it.
If creationists actually took the time to understand evolution instead of assuming it will disprove your god if you learn it, you may be pleasantly surprised to see that not only does it not disprove any god concept, but that you also already accept evolution, you just don't know that your "variations in kinds" is evolution. Instead you say "dogs don't come from cats" or something equally ridiculous and then in the next breath you describe a crude form of evolution that you believe. Just actually learn it and understand it and you will find that it fits perfectly within your beliefs and may actually strengthen them.