The button to the left of the Topic title indicating that there are unread posts in the topic will take you to the first unread post, regardless of the number of pages. That is how it should work. However, I have found it's functionality to be erratic. Sometimes it takes me to the first unread post. Sometimes it take me to the first post, the OP (original post).
Now need to learn to do Red.
Unless you have accidentally clicked the "Source" icon on the far left of a text window, the color icon will be available. If all you can see is the "Source" icon, click it and the other icons will appear.
The color button is the A with a down arrow next to it. It is near the right end of the toolbar, next to "Size." Click the down arrow and the colors will appear. If you want it bold too, that icon is next to the "Source" icon/button.