I've been dying my hair all colors of the spectrum the last few years. I've had so many people ask me questions or give compliments on my hair, so I've just decided to make a quick tutorial on how I color my hair. Disclaimer: I'm not a licensed cosmetologist, all the information is from my own experiences and attempt to dye your hair at your own risk.
If you have dark or dirty blonde hair, you will probably have to bleach your hair in order for the color you want to put on it to show up. You can choose to just slap it onto your hair, but you might only get a tint of the color in the sunlight then or it'll just subtly change the tone. Before you pick up bleach at your local Sally Beauty Supply, please research into how to use it because improper use can cause sever damage to your hair. Though you can safely tell your family and friends your hair won't fall out from bleaching and dying it... just don't over process your hair (dye it too much, too fast).
Make sure the color you decide to put on your hair suits your complexion because if it doesn't, then it will look odd and/or bad. If you do get the right color, it will look awesome.
Be prepared for it to wash out gradually and have to reapply the color often. Also note that washing your colorful hair in cold water preserves the color longer.
If you do decide to dye your whole head a different color, then be prepared to manage your roots. That is my friend applying bleach to my hair while the bleach I applied to hers is processing.
Last of all, just have fun with your hair and do it safely because in the end, it all grows out anyways. Do what you want with your hair and don't let society or anyone else tell you otherwise... unless they are giving you constructive criticism like 'that shade does not match your skin tone'.