Sperm Color...What's the difference?

What is the difference between the different colors?

Ive seen:
Colorless (color mine is…)
White (in porno movies)
Light brown (happen to me once… don know what to think)
Anyways… Whats the best color to have? and are the other colors bad?

From JackinWorld.com:

Lumpy semen is also within the range of normal. A urologist told me it’s nothing to worry about.