Can really different people really be together?
Is it possible for me to have a boyfriend who is a different age, color and personality than me?
Yes. Otherwise, you'd be dating your clone.
Age - Many successful couples have age gaps in them. The most important thing is that you and your partner feel like partners, so there's no imbalance there. A big pitfall in age-disparate relationships is that one person dominates the other because of seniority, life experience or even money. This kind of inequality can create unhealthy dependence, breed resentment, or simply make it really hard for you to relate to your significant other. When it comes to Age of Consent (AoC) laws (laws that make it illegal for adults to have sex with minors), you will need to look at your local statutes. AoC laws vary by state and country. But as far as I know, there is no place that forbids dating between people of certain ages.
Color - I like to believe that our society is enlightened enough to accept interracial relationships. In 1967, the last American law banning interracial marriage was defeated in the landmark court case Loving v. Virginia. The numbers of interracial marriages is rising, as it popular opinion supporting the practice. After all, we should judge people by the content of the character, not the color of their skin, right? Right. For most part. But the world isn't perfect. Racism still exists. Some people cling to obsolete notions that we should only be with "our own kind," and they'll look down upon anybody who dares to behave differently. Worse yet, hate crimes do happen, and there are bad people out there who would harass or do harm to people who love people who don't look different from themselves. So if you think you might fancy someone of a different race, consider whether the social climate in your region will allow you to be together without harassment.
Sometimes the pressure to date the same race isn't from the outside, but within. If you expand this to include different cultures and not just races, then you need to ask yourself if you are comfortable being with someone whose values and practices may be different from your own. If you're a Christian, would you feel okay dating a Muslim? If you're Latina, would you feel comfortable dating an Asian? Would you feel comfortable going out with an immigrant from another country? While many people are afraid of the unfamiliar, many people are enriched by their experiences learning about how other people live, think and behave.
Personality Traits - Do opposites really attract? Sometimes, yes. Sometimes, no. This depends on what you're okay with, and what bothers you. A quiet person could get along with a loud person. But if the loudness gets on your nerves, then chances are you're not going to like him or her. Sometimes, a really high-strung person does will with a really mellow partner because the mellowness can withstand hot tempers or mood swings. But sometimes, the melodrama is too much for the mellow-cat to take, and the relationship fails. Ask yourself if you generally like to be around people whose temperament and views are like yours. Or can you appreciate a contrasting opinion and disposition?
Personally, I think it's good to have a broader view of the world and get to know lots of different kinds of people. But the most important thing is that you feel comfortable with your choices.