As far as I know, when using a possessive s, you are also suppose to use a comma. For example "John's skateboard".
Yes, you do use apostrophes when using a possessive s ... apart from when you use the word it as the possessor. So yes, you go bear's food, cat's tail, John's skateboard, but Its food, its tail, his skateboard.
You can believe me on this one ... I teach English amongst other subjects for a living and that is one thing I know for sure. It is just one of the many idiosyncrasies about English that make it so wonderful to teach.
As far as the color, I replaced green and blue with light green and light blue. Please let me know if you still have trouble reading it.
Yes, those colours makes it much easier on the eye, thank you.