What am I?

I am a king but also a measuring device. What am I?

With the rich I am blue, with the poor I am red, with the amphibian I am cold but with the dog I am hot instead, What am I?

I cannot hear or even see, But sense light and sounds there may be, Sometimes I end up on a hook, I can be combined with a book. What am I?

I am a portal to another world which you cannot enter. Only you can see me but I can’t see you. What am I?

Riddles and Answers