Perhaps it's because you're a freshman, and a year younger than me. Or maybe you're unfamiliar of netiquette outside of Friendster.
Nevertheless, you do not post in intellectual discussion fora using rainbow-colored sentences. There's no need to color your sentence, and changing the color after each sentence. True, this shows uniqueness, but, please, keep it in social networking sites or your personal site or blog. You can even attach glittered blinking marques or something, but in a educational medium, this is a big NO.
Also, please align your post to the left, or justify it. Do not post it center-aligned. What you're posting is not a poem.
Finally, if you do decide to use colors, it's okay if you use one for the entire post. However, do not choose yellow for your text against a white background, as they burn my goddamned eyes.
Your seventeen year old classmate,