Right click on the Whisker Menu panel item. Then select Edit Applications. If you do not have this option, then install MenuLibre by pasting the following in terminal:
sudo apt-get install menulibre
Log out and in again so the option Edit Applications will not be grayed out / disabled.
In MenuLibre you can customize the Whisker Menu to your liking. You can create categories, change the name of a program, and change the icon of a program or category, etc.
- To add a category, click the plus button in the top left. Select Add Directory. Be sure to save it by clicking the down arrow button in the top left.
- To change the name of a program just click on the program name to edit it. Then save.
- To add a launcher under a particular category (directory), first click on that category. Then click the plus button to add your Launcher.
- To customize the icon and use your own image, click on the icon.
- To change the ordering of menu items, click on the down and up arrows in the bottom left.
- To remove a program or category click the trash icon at the top.
You can also change the background color, text color, etc. in Whisker Menu. There is a tutorial here from the developer.
You can use a website such as this one for your hexadecimal colors.