color blindness

I heard you cannot be color blind. I can't pass those tests with the dots and you try to see the number or shape within the dots. but i can tell difference between red green blue.. it's just the colors that are close together. what does this all mean for me? will they give the test with the dots? or just to check if you can see color at all?


EDIT:
I just did an internet search adn saw someone post that the law merely requires that you can tell between red/yellow/green for traffic signals. is that true?

 

yea i can tell yellow/amber

 

awesome, glad to hear it.