Colored Tags Tag Cloud Widget gives you a widget with colored tags.
Just drag and drop the widget to the the widget area you would like to display the tagcloud and your done.
The widget has two options that can be configured. You can give the widget a title (you can also leave it empty) and you can define the number of tags that you would like to display. Besides this you can also configure which colors should be used.
You can check it out live on these website (Scroll down and you see it in the sidebar):
For requests of new features and more information go to the official page:
Colored Tags Tag Cloud Widget
Arbitrary section 1
Added information on the plugin
Changed textfield to textarea so there is more space to enter colors
It is now possible to configure which colors you want to use (HTML colorcodes)
Changed the colors a little
Some color changes and title is now empty by default and can be changed if you want
Made default title of the widget empty