Like the others have said, all kids are different, so everything you read is just a guideline. Also, some kids seem to focus on language skills first while others are working on gross motor skills or something else.
We just had my son's 15-month check-up, and they asked if he was saying at least 3 words besides mama/dada, so that must be at least one guideline. My son has at least that many words, but they're not clear words that anyone can understand. He says things like "nah-nah" when he wants to nurse, "nana" for banana, and "huh-tuh-tuh-tuh" for hot. He also makes lots of animal noises and uses some signs/gestures to communicate. He does have a good understanding when we talk to him.
I don't think most kids are starting to identify colors/shapes until around age 2 although I can't say I remember exactly with my girls (they're now 4 and 5).
16-month-olds can definitely start to identify objects/characters in books, though. When we read to my son, we also talk about the things on each page (if he seems interested). We also talk about the colors and even count how many of something there are. If he's impatient just to read the book, we move on, but if he seems inclined to learn more, we talk about it.
My three kids have been so different in the order they've reached their milestones, and they definitely have different strengths and weaknesses. All you can do is continue to expose your children to a variety of things and follow their lead as to what they're interested in and how quickly they want to learn.