You can use the quickapproach mentioned in other answers if you just want to change color. However if you are using Bootstrap than you should use themes so that look and feel is consistent. Unfortunately there is no built-in support for themes for Bootstrap so I wrote little piece of CSS that does this. You basically get tooltip-info, tooltip-warning etc classes that you can add to the element to apply theme.
You can find this code along with fiddle, examples and more explanation in this answer: https://stackoverflow.com/a/20880312/207661