You can edit the options for your tooltips in the
Settings >> Tooltip CK page.
Here is an overview of the options.
This is an overview of what you can do (these options may vary depending on the new versions and upates coming).
Colors and styles
You can give the appearance of your tooltips, the background, text color, shadow, and so on.
Dimensions and position
Give the width of your tooltip. You can also set a general offset to place your tooltip in a specific position relative to the text.
Note that the width and position can be overridden for each tooltip using the custom parameters.
Text to hover styles
You can also set some style here, but this is specific to the text that you will hover. This is usefull to tell your user / visitor that it must put the mouse over this text.
You can select how you want your tooltip to behave. Set the durations for the effects and select how to place and open the tooltip.
Enable html fix option if you have any problem of rendering in your page when using the tooltip. This will help fixing the html errors like opening of closing tags missing.
Be careful, this is no magical and this can not fix any problem. You must have a look at your source code if you want to write some advanced html code in the tooltip.