Pretty good basic's but those are only what magic can and can't do and what it is. Good post, I suggest posting a full list on articles instead of forums.
Magic works with non-physical (often called subtle) energy. The reason magic does not work like popular media portrays it is because the physical plane is still bound by scientific laws.
Colors are light and vibration, thus being physical energy. One concept a lot of people ascribe to is that what is physically reflects spiritually/subtly. If colors are physical energy, then they are subtle energies as well. Obviously the associations we put to colors differ culturally and personally as we all interpret things differently, but that does not mean "magic has no color"; it does, it's just not the concept that different types of being relegated to one specific color like you find in the card/video game Magic: The Gathering.
The quote was originally used to combat fluffies and newbies whose only exposure to anything occult wise was through popular media. As time has passed, I realized that a lot of newbies that I've personally talked to are not under the impression that magic has literal color types. They realize it is a label, and nothing more. Even some of the more seasoned practitioners will use color labels in magic for ease of showcasing intent as they drop the pretense that it's something to be shunned. I've also found this mentality to be specific to SoM. Other sites I have visted do not have the same concepts we do.
Continuing on from the first bullet point, it is true that we cannot change into a mythological creature. However, there is the belief called Otherkin that one has the spirit, soul, consciousness, or otherwise attributes or traits of a creature found in lore. It is up to each individual as to whether or not this is real, but it is a belief that most of the time does not infringe upon physical laws of science.
The first and third points also apply here, but I would like to add that this can venture into spiritual and subtle illusion, often times called glamor. This is where a spell or working aids in altering perception. An example of this is by making something more or less noticable to help find or deter people from finding something/someone. If someone does a spell to help others perceive them as more beautiful (which is commonly sought out), and it is coupled with knowledge of psychology and mundane ways to portray appearance as beautiful and confident, then by all means, this is a valid practice. Most spiritually inclined people scoff at it because they view it as shallow and lesser. Again, I find this is a SoM mentality.
I want to add that that even if a spell is valid, no spell will work 100% of the time all of the time. there are various factors to consider when working a spell or ritual and what exactly those factors are will depend on the specific belief system the practitioner has.
