I hope no one actually has to read this text... jk
I don't think it's possible with CSS. You will probably have to use some kind of color transform to apply a gradient to the display object containing the text, or perhaps you can parse the FTE textLines and apply the transform there (could be more or less efficient depending on your needs).
As for the different color of each word, you will have to parse the TextFlow and apply a TextFormat for each word boundary in the flow. Its hard to give specifics without knowing anything about your requirements.