It seems basic enough, (and im fairly sure it doesn't work with all browsers) but have you tried the <blink> command?
For basic HTML text, the command looks something along the lines of:
< Blink >< font color ={html colour}>< / font >< / blink >
But its been a long time since ive done anything like that, and like I say, fairly sure it doesn't work with all browsers.
Theres probably some much better and more advanced way of doing it!