Right.
When you click on New Mail, the New Mail page opens ready for you to input who to send to, subject etc. When you click inside the box where you type your message, do you see the Font & Font size box above where you type your message ? Then along the same line, you'll see other font choices of B (bold) I (italic) U (underline) and then a letter A which is underlined. If you click on this, you'll get a drop down box of colours to choose for your font.
Easiest thing to do is type your whole message, the just highlight the bit's you want and change them to whatever font, size or colour you wish.
To change the background colour of a message, click on Format along the top, and go to Background and then Colour, and you'll get the same drop down colour box as before to select your background colour.
If you need to know any more, let me know
Happy, colourful messaging !
kwunder