We had the same problem to enable this kind of styling in the CQ5.4. Maybe there is this kind of feature in the CQ5.5, but honestly I don't know.
We achieved this using plugin "style" in the configuration of richtext. Please see following link for more details:
We created different styles for different font size, font colors and even font types. That's all.
Thanks for ur reply.yes even we did the same.Added styles for each color.
Came across enablecolors(true,false) for richtext. Just wanted to know whether that feature is available.
As I know there is no this kind of functionality, you can refer to widgets api and there is no this kind of function
You can try to customize richtext widget and add this kind of function or develop from scratch new plugin