It depends on how you describe dribbles out.
Do you mean when you ejaculate it just comes out and runs out and not squirts into the air.
All men are different and ejaculation comes in different flow rates, it does not have to shoot in the air like you see in porn movies.
And for the amount that does ejaculate that also can
come in different amounts, it can take just a very small amount to impregnate a female.
If you have a concern on the sperm colour you could seek advice from your doctor who can perform a sperm test.